Get in tech with technology with tech stuff from stuff. Hey there, guys, it's Jonathan from text Stuff here. And in our previous episode, we covered the first half of the Mogue story, but the episode became so epically long we needed to divide it into two parts. And so without further ado, let's jump back into the conversation with Joe McCormick about the Mogue story. Here's part two. So then you have all the different modules that actually will alter the sound of whatever wave you are creating. And again I'll talk about the specific wave forms in just a bit. But so some of the modules would include things like filters. You probably heard about filters, right, you know you run this through a filter. What filters are are doing is there specifically changing the harmonic content of a signal, and it lets you narrow down the range of frequencies that are allowed in any produced sound, like you can specify which harmonics are allowed to go through, which ones are not allowed to go through, and that alters the quality, the tonal quality of any sound you make. So I'm going to start talking about some particular filters, and our producer Extraordinary Knowl is going to provide us with some examples of some of the stuff we talk about. So from this point forward, uh, Noel is really gonna have free rein to go crazy Broadway style. I encourage him highly to interrupt us as often as possible with strange noises. If he hasn't already, I expect him to do so from this point forward. As the wonderful thing about Noel not being in the room where we record, we have no way of knowing what he's going to add after this is done. But at any rate, Uh, so you can you can change the amplitude, which obviously changes the volume, and you can change the frequency, which changes the pitch. Those are very basic eight but beyond that you can start to really have fun with it. So filters are ways to change the timbre of the sound, even within a single note. So you can press a note with no filter, it's gonna sound one way, and then you apply a filter and press that same key to create that same note, but it's going to have a different quality. So one of the basic types of filters would be what's called a low pass filter or a high pass filter. Very simple concept. The name tells you what it lets it do. So a low pass filter and let's low frequencies pass through. It blocks high frequencies. Now you can define what where's your cut off, so you can say, like any frequency above this is not allowed through. Anything that's lower than that can go through. Now I'm gonna ask the question I think some listeners may be wondering, Hold on a second, why would there be multiple frequencies playing when you've got a single tone playing? Shouldn't that be one frequency? If you're playing one pitched note, you could be playing one pitch note if you're if your wave is just a sign wave, right, A sign wave is a pure tone. It means it's a fundamental frequency. There's no harmonic added to it. But that's the That's only one type of waveform you can play with a synthesizer. You can actually create different types of waveforms like saw tooth waves or square waves or triangular waves, and each of those contains harmonics. Harmonics being uh multiples of your fundamental frequency. Your fundamental frequency is always going to be the loudest, the one with the greatest amplitude. Right, So the note you're playing, there's a specific frequency associated with that note, its amplitude is going to be the greatest in the full sound wave, but with these other wave for triangular square and saw tooth, you get multiples of that particular frequency that also show up, and those are harmonics. But if you don't want to hear any of those high harmonics, you just want that deep, nasty, bassed rumble. Yeah, you can do it a low pass filter. And what that does is it actually you would think it would be like a really base sound, but it really kind of makes it sound sort of muffled and dark. And then if you wanted instead to do the opposite, you could put a high pass filter. On high pass filter, obviously the higher frequencies are allowed to pass through and it blocks the lower frequencies. Sounds kind of bright and jangle exactly much much brighter sounds. So Noel, I'm sure can give us examples of what sounds like to listen to some tones played through a low pass filter and some tones played through a high pass filter. There are a couple of others that I want to mention that also are our pass filters, but they are a little different from low and high. Uh. There's the band pass filter, which allows a group of frequencies that are between the high and low ends. To pass through. So in other words, you're saying, alright, anything below this frequency, I want you to cut out. Anything above this frequency, I want you to cut out. Everything in between can pass and that gives you a different sound or band. Reject filters which specify a specific range of frequencies that are not allowed to go through, but everything else can. So it's essentially like bouncers. Okay, here's a list of people. They absolutely are not allowed in the club. My name is always on that list all the time. At least that's what they tell me. Um, but apparently my friend, uh, Benjamin Franklin, he gets in all the time. Now, beyond those filters, you can do some other fun stuff. For one thing, you remember I said that an analog sound wave is continuous of course, right, so it doesn't have a quick, you know, a discrete value where there's a stop start. Partly because of that, cut offs like where you said, here's where I want the filter to begin are a little hazy. So uh, when you when you have your these uh these filters, you also have a transition band. The transition band is a small band of frequencies that will still play through where you've set your cut off. So, in other words, if you say you're cut off is five thousand hurts, anything below five thousand hurts, cut that off. It's not a hard stop at that frequency. There's actually it trails a little bit, which gives kind of an interesting effect. Right, So that's really cool. But beyond that, you can start to do things like adjust a filter while you're actually playing a tone. You can do this by hooking up different modules together. I'll talk about some of the other modules in the second. And that's where you get like, like the frequency of wah, well maybe because I mean it's the way it sounds like the pitch. The pitch remains the same, but the tone of the of the note is different, So the pitch doesn't change, but the the quality of the sound changes. Noel, I'm sure it could play for us the sound of a note where the filter is changed while the note is still playing, so that we can kind of get an idea of what that sounds like. And another thing you can do is play with resonance. Uh. And one way you can play with residents is you take the frequencies that are close to that cut off frequency where you know you've you've set the filter boundaries, and instead of just having them play out to a speaker, you feed them back into the filter. This creates a feedback loop and I believe it's called a lope. How many more times are we going to have that joke? All right? So it creates a feedback loop, and it also changes the timbre and volume of of the pitches that you're playing, which is really cool. Um. So that's all in just talking about filters. There are other modules that we can mention that. That's just one subset of modules. Another one is called the envelope generator. You know, there's a great scene in that documentary where I don't know if you saw this one because I think you so part of it where Bob mog himself is showing off one of his machines and he he sort of like rubs his hand luxuriously over the envelope while he speaks of it. Does it give uncomfortable? No? No, no, it's kind of suite. You can tell he you know, he has he has a love for this envelope. He has a relationship with this envelope. And you might wonder, well, what the heck is this thing? Anyway? Well, it's another section of the board. Yeah, and and it's as you might imagine, as we're talking about these different oscillators, these different waveforms, and these different filters, it's already starting to sound pretty complicated. I mean, you've got all these different knobs and stuff to control things, and maybe you want to have various effects apply to your music, but you can't by hand constantly adjust this, or employ a second person too on the fly make these changes to filters so that the notes you produce have the quality that you want. Envelopes are kind of like macros in the software world, where you make shortcuts where you hit control and a letter and suddenly it creates like a a series of commands that otherwise would take you multiple mouse or key strokes to actually execute the same sort of thing. Except in this case we're talking about analog circuitry UM. So envelope generators can react to an incoming signal and then send out a new signal to a different module. And so it's another if then gates. So if signal X comes into the envelope generator, then send y signal to this other module so that you get the effect you want. And one type of envelope generator one common one is the A D S R, and that stands for attack, decay, sustain, and release, which are kind of like four phases in a note. So have you ever played with a synthesizer where you pressed down on a key and the sound kind of comes up to a level and then backs off just a little bit. Oh, yeah, that's the slow attack. That's the attack. Yeah, that's the attack in decay actually, because the rise involvedvolume is the attack when it hits its peak and starts to come back down just a bit. Like let's say that there's a scale of zero to one. You press down the key, it goes from zero up to one, then it falls back to maybe point seven. That that fall back to point seven would be the decay phase. So the attack phases going from zero to one decay than one to point seven. That part happens usually pretty quickly, right, And then you still got the key held down. As long as you have the key held down, the note is playing, that's the sustain. When you release the key, you get to the release phase, which trails the note off. And you can adjust all of these things. You can adjust it so that the attack takes longer, so that the build up to the peak and then the decay is more you know, it's it's taking kind of the scenic route. Or you can make the release last a really long time so that the note trails off like you have a long, sort of sustaining note. Um. All of these are things you can adjust using this type of technology, which gives you an incredible amount of flexibility when you are trying to create a specific sound. And one of the things that I think really makes synthesizers in general, and the mogue in particular, incredibly special. It makes me wish that I were capable of playing one. UM. I only plink around on keyboards, so it's pretty pathetic. Noel is like a master Jonathan. What's the song you always play when you sit down at a piano. Everybody has that annoying thing. They do the one song they know how to play, and they sit down and they do it well. There are two songs that I tend to play. One is the theme to Raiders of the Lost Arc. I mean, that's great triumphant music and it's Nazi killing music, it is. And then the other one is Jesu joy a Man's Desiring. That's that's kind of two that I do, but I also I've also been known to do, oh de joy. Okay, so that's a bit of the old lidig, that's right. I have been obviously the the actual de joy movement, which is from you know, a much longer symphony, the Ninth Symphony. It's only that one section that I do. I can't play the any of the rest of it. And I can't really play that one very well. It's like two finger typing. It's like that, except with keyboard. I'm sure you're an astonishing blinker. Yeah. Occasionally, you know, if I get want to get fancy, you know, chopsticks, that's where it's at. A big fan of the Jaws. Yeah, nice, nice. I've been known to to do the uh, the musical motif from Close Encounters of the third kind um, which you can play just on the black keys. There's one other thing I want to mention um. A couple other things actually. One is the low frequency oscillator low frequency office oscillators also known as lfos UH. They control other modules by sending a low frequency. It's so low that sub audio you can't you can't hear it. It's beneath it's below twenty hurts um and they send a signal to other modules to alter a set sound. So this is one of the ways you can make that uh that sort of vibrato sound in a sustained note is altering this by using a low frequency oscillator gives it that wave equality maybe Noel can demonstrate. And then you can always use a control signal to change the frequency of another module. That's called frequency modulation or f M. By the way, all these things I'm talking about about changing frequencies of electronic signals. It doesn't just apply to synthesizers like frequency modulation oscillators, changing these things. This is all basic electronics, whether you're making a sound or doing something else. It's not just in in creating music. But where of course specifically framing it in that because the topic is the mogue. Uh So these are all super cool elements that give the moge that that quality it possesses, that really unusual sound, that that unique sound maybe instead of unusual, I wouldn't want to say something that would have offended mog himself. By unusual, I mean unique, not bad um And uh yeah, you can these things could get monstrously huge, like I've seen synthesizers that didn't have any keyboard attached them at all. It was just the various modules to demonstrate what the modules do. So all you had were the various modules, cables to hook physically hook the modules together, pugging and unplugging cables and turning dials, and you would have have maybe in a scilloscope to see the wave form, so you had something visual there too, but it was all just plugging and unplugging cables, patching in the alters, taking filters out by directly connecting modules. You know, that's interesting because when when mog and Deutsch were originally designing the mode, the you know, the synthesizer that would maybe it was the Abomba Atron, I don't know the original model. They were talking about the idea and they were discussing whether or not it should have a keyboard. The keyboard is sort of the obvious way to control the variable of pitch. But the question is should we have gone with something else, because does the keyboard inherently suggest this is really just a different kind of piano, which modified piano. You should approach it like a piano, use it like a piano. You bring your piano playing behaviors to the machine, and they were they were torn on that because they were thinking, well, what if we didn't include the keyboard, might that help encourage people to use this to generate sounds in a way that's truly new and doesn't mimic the way we've used other instruments before. Of course, we know they did end up going with the keyboard, and that kind of makes sense because the keyboard is a very useful and intuitive way to control pitch, but especially when you get to a point where you're capable of producing more than one one tone by pressing more than one key at once, right, some early synthesizers were only capable of performing like you press one key and that's the sound you would get, but you would not be able to create harmonies with some early synthesizers where you know you were if you change from key to key, you change the pitch, but you couldn't hold down a chord and have all three notes play, and some early early synthesizers. I think that's the case with the mog and it I believe so, and that that would mean that you could change out the keyboard for something like a lever. Then you pull the lever, and maybe when you pull the lever in one direction the pitch increases, and when you put push the lever the other direction, the pitch lowers. That could have in the control device or anything else. Really it didn't have to be the keyboard, but they decided ultimately to have the keyboard because again it I think you're right. I think it makes it easier to understand how to produce the sound you want to produce. It becomes less It slightly steps away from the element of performance art the way a theoreman kind of is like, you can get a really skilled theremin player to create particular sounds and even play particular pieces of music, but it is hard. It is is It is an art to learn how to do that, and even then it's very imprecise. I think they probably should have replaced the keyboard with a big, big row of holes filled with a putty like a google that you have to insert your fingers into to play the note. Starting to make me think of like some sort of combination of a musical instrument, and that the Tree of Death and Flash Cordon reach inside and discover the true tones of the future. Right, So, uh, let's talk about waveforms because we mentioned them a little bit with sign waves, square waves, triangle waves, sawtooth waves. What what the heck to all of these mean? Um? And we've already talked about what a waves period is, We've talked about frequency and amplitude and uh. For for a lot of this, I'm going to be looking at using the example of a one hundred hurts um wave or frequency rather one hundred hurts frequency, so that it makes it easy for me to use the math to describe the different wave forms, because if I go with something that's not easy, then I would have to do a whole bunch of different calculations of the So I mentioned earlier, sign waves are that pure wave, is that fundamental frequency? Uh? This would be the same as if you were to take a tuning fork and ring it. It's going to create a true tone with no harmonics. It's a single sound. Uh. And so at one hundred hurts, you would have a wave where it's period is being repeated one hundred times every second, and that's all you would get just that, and it would be at a steady amplitude unless you were adjusting the volume. So again, amplitude refers to how loud it is in this case for for sound. Uh. And also what's really neat is that you know, you we depict this with the the peaks and valleys on a on an X Y axis, whereas the like the x axis the horizontal axis that represents time, and the vertical axis represents the the amplitude the volume. Uh. If you were to match up two sound waves that are identical, but the peaks of one sound wave are matched with the troughs of the other sound wave perfectly, they cancel each other out. So you play these two sounds simultaneously, if they line up in that way, they cancel one another out. It's like it's like all the atoms can't move because they're pushing against each other and not actually creating the vibration required for you to hear a noise. Noise canceling headphones work on a pretty similar principle to this to some degree. So that's kind of interesting. All right, So let's talk about saw tooth waves. If you look at these, it looks like a ramp and then it's like the ramp goes up into the right and then immediately drops off like has a vertical drop, and then moves up into the right again, and that's why it's called saw tooth. It looks like the teeth of a saw blade. Um These when you play them, have a buzzing sound that's really strong and clear. So this is what a saw tooth wave sounds like. Now, those are made by combining a series of sign waves at different frequencies and volume levels. The loudest sign wave defines the frequency of the overall saw tooth wave, and that is the fundamental frequency, and the other sign waves represent the harmonics, which are deally at a frequent that complements the fundamental one. So generally what we talk about are multiples of the fundamental frequency. That's why I'm going to start with a one hurts. So at a hundred hurts, your next multiple like harmonic harmonic. The first harmonic would be number two because number one is your fundamental that's one hurts. Number two would be two hundred hurts because it's the multiple that's the harmonic. Number three is three hurts, four is four hundred hurts, so on and so forth. Multiple and harmonic number are the same thing as what I'm trying to get across. All of those are playing at the same time. But the amplitude of the harmonics is lower than the amplitude of the fundamental frequency, meaning they're quieter, right, They're not overwhelming, Otherwise you would just have noise. So uh, it drops with each step further away from the fundamental frequency, and it stretches on effectively into infinity. Eventually it gets to a point where it's so low that it's impossible for us to understand. So yeah, while the wave effectively or the the harmonics effectively go on into infinity, eventually one you hit a frequency that humans cannot perceive and to its well, in general, humans have trouble perceiving, and it's at an amplitude that's so low that you wouldn't be able to hear it anyway. The volume is too low for you to be able to detect it. But that's the that's what gives the saw tooth wave that tonal character. Then you've got square waves, which look very square. I mean, if you were to look at they almost looked like like the the battlements you might see on the top of a castle wall or something. And uh, square waves contain harmonics like a saw tooth wave, but it only contains the odd numbered harmonics, So you don't have harmonic number two. If you start with one hundred hurts, you wouldn't have two hundred hurts as a harmonic. It would be skipped. But you would have three hundred huh and five hundred and seven hundred and nine hundred. But you skip all the even numbered harmonics. You only include the odd ones. And there's an actual formula for how quiet those harmonics arery What you do is you take the harmonic number and then you do the inversion of that. You invert it. So harmonic three you would invert to one over three or point three three three three, it would have that. That would be its amplitude compared to the fundamental frequency. Five would be one five of the amplitude of the fundamental frequency. Seven would be one seven, etcetera, etcetera, all the way down the line. So a square wave is going to have a a tone that a lot of our listeners are going to recognize because it's the type of wave generated by classic video game console systems like the Nintendo Entertainment System would be a great example. Yeah, so you gotta stop, you gotta stop and tell me what's your favorite in nes eight bit video game music. Uh. I know it's kind of lame to go with such a popular answer, but I really like the Legend of Zelda. That's a great one, you know. I also really I really like Super Mario Brothers. It's great. I really remember liking the music that went with the old ne ne Nes Batman game, which the only movie based games for the NES that wasn't horrible. Yeah, it wasn't wasn't like a just a complete travesty of the franchise rights. It was pretty good game, you know. That's what I'm saying is that that's great music. You remember Do Do Do Do Do? And I never owned it in ne e S, but I have a friend who did, and he had that game, so I do remember that. But anyway, this is what those square wave forms sound like, in case you wanted to know. So, yeah, you could tell. They're a little a little less buzzy than the saw tooth waves. The square ones are slightly less buzzy, but they still have some character to them. And then we have triangle waves. Triangle waves hate person waves. They have a fight triangle wins. Also, they have a really more mellow sound than your square waves or sawtooth waves do, so they kind of sit between square waves and sign waves. They also have harmonics, and they also have only odd numbered harmonics like the square waves do, so just three, five, seven, nine, etcetera. You don't have any even numbered harmonics in the triangle waves. And in this case, the amplitude of the harmonics is the drops off faster than it does with the square waves. So in square remember it's the inversion of the harmonic number, so three is one third, five is one. Five with triangle waves is the inversion of the square of the harmonic. So it's one over three squared or one over nine or point one repeating. So that's it's that amplitude compared to the fundamental frequency. And then etcetera down the road, so it'd be one over five squared, one over seven squared, one over nine squared, etcetera. And that would be your amplitude of your harmonics to the fundamental frequency. Ah, so that that's your basic ones. Oh, in a triangle wave, we should definitely hear what that sounds like. It sounds like this, So those are your basics, like that's you know, those are your the basic qualities of sound you could use. You could you could choose which type of wave you wanted the oscillator to generate with your moge synthesizer, and then put that through the various filters and other modules that we talked about to create all sorts of interesting sounds and and really give your music a very interesting character before you even start playing a melody. So with all of the richness of a variety of electronic music that you can create with synthesizers, I mean, we're focusing on analog synthesizers today, but really with any kind of electronically gym rated in music, there's a lot you can do. Why do why does some people still regard it as fake music? Because some people just I think are narrow minded jerk faces. No, I don't want to, I don't want to really suggest that. I think I think though, this is one of those things that historically we've seen repeated, you know, many times, even before the age of electronic music at all, we saw this, like just with composers styles and you you've heard stories of how after the performance of a particular symphony and audience might riot in reaction because it was so different from what came before it. And I think that's part of it. I think there's some people who just have trouble accepting the idea that something different from what has come before has any can add any value, and if it doesn't fit their definition of what is music, it therefore cannot be music. Um, I don't believe in that. I mean, I will go so far as to say, like, there are there's definitely some experimental music out there that to me sounds indistinguishable from random noise. Like there are some performance aren't pieces, and some of them are meant to be like that, like dropping objects onto piano wires from like twenty feet up so that you could create these these loud noises. It's not like that's done with surgical precision to create a very specific sound, and that's not what the intent of the piece is. Uh, and it it's it gets tricky for me to refer to that as music because it doesn't fit my definition, my personal definition of what music is. So I'm even guilty too of that to some extent. You know, one example I think of that that comes up is, for example, drum machines. Yeah, you hear that criticized all the time. People are like, oh, you know, the music these days, any idiot with the drum machine can just make some loops and then and then there were a musician, and that's not real music, or or people who program music into like it's possible to program music into a computer file without ever touching any kind of musical instrument. Right, You could, in theory, create music just by manipulating numbers if you have a great enough affinity for that. I don't think that makes the music any less valid than anything else. I don't think that there should be a In fact, how different is that from being a composer who creates, who composes music for a symphony and doesn't play it him or herself. Right, Yeah, I would argue that is very similar. And and I also just think that that the creation of music goes beyond how skillful you are at tickling the ivories or being able to plug strings. What did you just say to tickle the ivories? Tickle the ivories? That's playing piano? Where on earth did you learn that expression? What are you? Are you kidding me? Look, tickle them, tickle the ivories? You've never heard this phrase? Are you telling me that? Oh my gosh, well I am older than you are. Uh, tickle the ivories is a phrase that means play the piano. Okay, I guess. I guess I'll just have to go home and beat up my guitar. Well, I'm just saying a phrase that doesn't matter at any rate, Like I don't I don't think. I don't think that musical ability. I'm gonna go roughly chop my drums. I don't think that. Look, I'm about tickling the ivories and you're going into abuse. I don't think of all the bizarre things you can do with your hands that are not playing a musical instrument. Okay, Well that's that's fair. So I'm sorry. Now I'm the one being judgmental. I apologize, Jonathan. I think you should feel free to tickle the ivories however you like, and and I won't judge you for it. I just can't believe you've never heard that phrase before I heard. Well, it's it's pretty common down my way. Um. But at any rate, we had a lot of ivory ticklers when I was growing up. Um. So at the point being that, I don't think that there's any particular skill that you have to possess in order to be someone who makes music other than the ability to create a melody or or you know, to actually create the music in whatever whatever mode you use to do it doesn't matter well, I mean regardless, Like why would we even consider ourselves in the business of certifying what counts as being a musician or not? This? Like, why is that our job to tell people, no, that's not real music. This honestly reminds me a lot of the debate of whether or not video games or art or video games just contain art. So in other words, like, yeah, the graphics in a video game can be considered art, the music accompanying a video game can be considered art. But is a video game itself art? And there's people who very violently say absolutely not, there is no way a video game itself could be art. Do they have some kind of like philosophical principle in forming this opinion? I think they just have some sort of ridiculous narrow definition of what they think art has to fall in. Yeah, so I would say that this that the electronic music has fallen into that same thing that some people. For them, they have a very narrow definition of what music is. An electronic music falls outside of that definition, so therefore it cannot be music by by definition. Problem is that's not everyone's definition. I have a much broader opinion of what is music, maybe not as broad as other people. In fact, certainly not as broad as other people. I know there are folks who like music that I just find uh baffling, like there's no appeal to me. So I know that I'm also guilty of that, but I'm at least aware of it. So that's the story of the Moag synthesizer, what it did, the the actual wave forms that are produced, and how those come together to make various sounds. I gotta thank you, Joe for being on the show and joining me to have this discussion. It's been like you for inviting me. And I have to thank Noel for all the amazing work he will be doing on this episode that I have not yet heard because obviously he'll be adding it in later, but I can't wait. He was very eager to do it, Joe. You know, Noel is like he's crazy talented when it comes to music. Killer He he composed created the new music that the new theme music we have on over on stuff to build your mind, which I much preferred to the old theme music. He also did the music for tech stuff, which I much prefer to the old music. So yeah, Noel is a is a kind of a amazing and he's always working on something. Um Actually, one thing I would love Noel to do at some point, I'll have to do another episode about music so that Nol can play some of his mouth noise symphony for listeners, because he's created musical pieces where all of the all of the sounds come from various mouth noises. They's cut out of podcasts and then manipulated in some way to make the musical and you would not necessarily know that it was a series of mouth sounds if you listen to it without being told first. It's kind of cool as the sort of thing he does him he can really tickle the mouth sound. You really can. I can't believe you're giving me crap about this very valid phrase that when you google it you are going to be shocked that there are other people who have used it. Okay, well, and that we're going to wrap this up. This has been an epic episode about Mode. It's been fun and guys, if you enjoyed this episode, please let us know if you have suggestions for other topics or suggestions for people I should get on the show, either as a guest or an interview subject. I'd love to hear from you. Send me an email that address is tech stuff at how stuff works dot com, or drop me a line on Facebook, Tumbler, or Twitter. To handle it all three, it's tech Stuff hs W, and I'll talk to you again. Really sat. For more on this and bathans of other hathics, visit has stuff works dot com.

Get in tech with technology with tech stuff from stuff. Hey there, guys, it's Jonathan from text Stuff here. And in our previous episode, we covered the first half of the Mogue story, but the episode became so epically long we needed to divide it into two parts. And so without further ado, let's jump back into the conversation with Joe McCormick about the Mogue story. Here's part two. So then you have all the different modules that actually will alter the sound of whatever wave you are creating. And again I'll talk about the specific wave forms in just a bit. But so some of the modules would include things like filters. You probably heard about filters, right, you know you run this through a filter. What filters are are doing is there specifically changing the harmonic content of a signal, and it lets you narrow down the range of frequencies that are allowed in any produced sound, like you can specify which harmonics are allowed to go through, which ones are not allowed to go through, and that alters the quality, the tonal quality of any sound you make. So I'm going to start talking about some particular filters, and our producer Extraordinary Knowl is going to provide us with some examples of some of the stuff we talk about. So from this point forward, uh, Noel is really gonna have free rein to go crazy Broadway style. I encourage him highly to interrupt us as often as possible with strange noises. If he hasn't already, I expect him to do so from this point forward. As the wonderful thing about Noel not being in the room where we record, we have no way of knowing what he's going to add after this is done. But at any rate, Uh, so you can you can change the amplitude, which obviously changes the volume, and you can change the frequency, which changes the pitch. Those are very basic eight but beyond that you can start to really have fun with it. So filters are ways to change the timbre of the sound, even within a single note. So you can press a note with no filter, it's gonna sound one way, and then you apply a filter and press that same key to create that same note, but it's going to have a different quality. So one of the basic types of filters would be what's called a low pass filter or a high pass filter. Very simple concept. The name tells you what it lets it do. So a low pass filter and let's low frequencies pass through. It blocks high frequencies. Now you can define what where's your cut off, so you can say, like any frequency above this is not allowed through. Anything that's lower than that can go through. Now I'm gonna ask the question I think some listeners may be wondering, Hold on a second, why would there be multiple frequencies playing when you've got a single tone playing? Shouldn't that be one frequency? If you're playing one pitched note, you could be playing one pitch note if you're if your wave is just a sign wave, right, A sign wave is a pure tone. It means it's a fundamental frequency. There's no harmonic added to it. But that's the That's only one type of waveform you can play with a synthesizer. You can actually create different types of waveforms like saw tooth waves or square waves or triangular waves, and each of those contains harmonics. Harmonics being uh multiples of your fundamental frequency. Your fundamental frequency is always going to be the loudest, the one with the greatest amplitude. Right, So the note you're playing, there's a specific frequency associated with that note, its amplitude is going to be the greatest in the full sound wave, but with these other wave for triangular square and saw tooth, you get multiples of that particular frequency that also show up, and those are harmonics. But if you don't want to hear any of those high harmonics, you just want that deep, nasty, bassed rumble. Yeah, you can do it a low pass filter. And what that does is it actually you would think it would be like a really base sound, but it really kind of makes it sound sort of muffled and dark. And then if you wanted instead to do the opposite, you could put a high pass filter. On high pass filter, obviously the higher frequencies are allowed to pass through and it blocks the lower frequencies. Sounds kind of bright and jangle exactly much much brighter sounds. So Noel, I'm sure can give us examples of what sounds like to listen to some tones played through a low pass filter and some tones played through a high pass filter. There are a couple of others that I want to mention that also are our pass filters, but they are a little different from low and high. Uh. There's the band pass filter, which allows a group of frequencies that are between the high and low ends. To pass through. So in other words, you're saying, alright, anything below this frequency, I want you to cut out. Anything above this frequency, I want you to cut out. Everything in between can pass and that gives you a different sound or band. Reject filters which specify a specific range of frequencies that are not allowed to go through, but everything else can. So it's essentially like bouncers. Okay, here's a list of people. They absolutely are not allowed in the club. My name is always on that list all the time. At least that's what they tell me. Um, but apparently my friend, uh, Benjamin Franklin, he gets in all the time. Now, beyond those filters, you can do some other fun stuff. For one thing, you remember I said that an analog sound wave is continuous of course, right, so it doesn't have a quick, you know, a discrete value where there's a stop start. Partly because of that, cut offs like where you said, here's where I want the filter to begin are a little hazy. So uh, when you when you have your these uh these filters, you also have a transition band. The transition band is a small band of frequencies that will still play through where you've set your cut off. So, in other words, if you say you're cut off is five thousand hurts, anything below five thousand hurts, cut that off. It's not a hard stop at that frequency. There's actually it trails a little bit, which gives kind of an interesting effect. Right, So that's really cool. But beyond that, you can start to do things like adjust a filter while you're actually playing a tone. You can do this by hooking up different modules together. I'll talk about some of the other modules in the second. And that's where you get like, like the frequency of wah, well maybe because I mean it's the way it sounds like the pitch. The pitch remains the same, but the tone of the of the note is different, So the pitch doesn't change, but the the quality of the sound changes. Noel, I'm sure it could play for us the sound of a note where the filter is changed while the note is still playing, so that we can kind of get an idea of what that sounds like. And another thing you can do is play with resonance. Uh. And one way you can play with residents is you take the frequencies that are close to that cut off frequency where you know you've you've set the filter boundaries, and instead of just having them play out to a speaker, you feed them back into the filter. This creates a feedback loop and I believe it's called a lope. How many more times are we going to have that joke? All right? So it creates a feedback loop, and it also changes the timbre and volume of of the pitches that you're playing, which is really cool. Um. So that's all in just talking about filters. There are other modules that we can mention that. That's just one subset of modules. Another one is called the envelope generator. You know, there's a great scene in that documentary where I don't know if you saw this one because I think you so part of it where Bob mog himself is showing off one of his machines and he he sort of like rubs his hand luxuriously over the envelope while he speaks of it. Does it give uncomfortable? No? No, no, it's kind of suite. You can tell he you know, he has he has a love for this envelope. He has a relationship with this envelope. And you might wonder, well, what the heck is this thing? Anyway? Well, it's another section of the board. Yeah, and and it's as you might imagine, as we're talking about these different oscillators, these different waveforms, and these different filters, it's already starting to sound pretty complicated. I mean, you've got all these different knobs and stuff to control things, and maybe you want to have various effects apply to your music, but you can't by hand constantly adjust this, or employ a second person too on the fly make these changes to filters so that the notes you produce have the quality that you want. Envelopes are kind of like macros in the software world, where you make shortcuts where you hit control and a letter and suddenly it creates like a a series of commands that otherwise would take you multiple mouse or key strokes to actually execute the same sort of thing. Except in this case we're talking about analog circuitry UM. So envelope generators can react to an incoming signal and then send out a new signal to a different module. And so it's another if then gates. So if signal X comes into the envelope generator, then send y signal to this other module so that you get the effect you want. And one type of envelope generator one common one is the A D S R, and that stands for attack, decay, sustain, and release, which are kind of like four phases in a note. So have you ever played with a synthesizer where you pressed down on a key and the sound kind of comes up to a level and then backs off just a little bit. Oh, yeah, that's the slow attack. That's the attack. Yeah, that's the attack in decay actually, because the rise involvedvolume is the attack when it hits its peak and starts to come back down just a bit. Like let's say that there's a scale of zero to one. You press down the key, it goes from zero up to one, then it falls back to maybe point seven. That that fall back to point seven would be the decay phase. So the attack phases going from zero to one decay than one to point seven. That part happens usually pretty quickly, right, And then you still got the key held down. As long as you have the key held down, the note is playing, that's the sustain. When you release the key, you get to the release phase, which trails the note off. And you can adjust all of these things. You can adjust it so that the attack takes longer, so that the build up to the peak and then the decay is more you know, it's it's taking kind of the scenic route. Or you can make the release last a really long time so that the note trails off like you have a long, sort of sustaining note. Um. All of these are things you can adjust using this type of technology, which gives you an incredible amount of flexibility when you are trying to create a specific sound. And one of the things that I think really makes synthesizers in general, and the mogue in particular, incredibly special. It makes me wish that I were capable of playing one. UM. I only plink around on keyboards, so it's pretty pathetic. Noel is like a master Jonathan. What's the song you always play when you sit down at a piano. Everybody has that annoying thing. They do the one song they know how to play, and they sit down and they do it well. There are two songs that I tend to play. One is the theme to Raiders of the Lost Arc. I mean, that's great triumphant music and it's Nazi killing music, it is. And then the other one is Jesu joy a Man's Desiring. That's that's kind of two that I do, but I also I've also been known to do, oh de joy. Okay, so that's a bit of the old lidig, that's right. I have been obviously the the actual de joy movement, which is from you know, a much longer symphony, the Ninth Symphony. It's only that one section that I do. I can't play the any of the rest of it. And I can't really play that one very well. It's like two finger typing. It's like that, except with keyboard. I'm sure you're an astonishing blinker. Yeah. Occasionally, you know, if I get want to get fancy, you know, chopsticks, that's where it's at. A big fan of the Jaws. Yeah, nice, nice. I've been known to to do the uh, the musical motif from Close Encounters of the third kind um, which you can play just on the black keys. There's one other thing I want to mention um. A couple other things actually. One is the low frequency oscillator low frequency office oscillators also known as lfos UH. They control other modules by sending a low frequency. It's so low that sub audio you can't you can't hear it. It's beneath it's below twenty hurts um and they send a signal to other modules to alter a set sound. So this is one of the ways you can make that uh that sort of vibrato sound in a sustained note is altering this by using a low frequency oscillator gives it that wave equality maybe Noel can demonstrate. And then you can always use a control signal to change the frequency of another module. That's called frequency modulation or f M. By the way, all these things I'm talking about about changing frequencies of electronic signals. It doesn't just apply to synthesizers like frequency modulation oscillators, changing these things. This is all basic electronics, whether you're making a sound or doing something else. It's not just in in creating music. But where of course specifically framing it in that because the topic is the mogue. Uh So these are all super cool elements that give the moge that that quality it possesses, that really unusual sound, that that unique sound maybe instead of unusual, I wouldn't want to say something that would have offended mog himself. By unusual, I mean unique, not bad um And uh yeah, you can these things could get monstrously huge, like I've seen synthesizers that didn't have any keyboard attached them at all. It was just the various modules to demonstrate what the modules do. So all you had were the various modules, cables to hook physically hook the modules together, pugging and unplugging cables and turning dials, and you would have have maybe in a scilloscope to see the wave form, so you had something visual there too, but it was all just plugging and unplugging cables, patching in the alters, taking filters out by directly connecting modules. You know, that's interesting because when when mog and Deutsch were originally designing the mode, the you know, the synthesizer that would maybe it was the Abomba Atron, I don't know the original model. They were talking about the idea and they were discussing whether or not it should have a keyboard. The keyboard is sort of the obvious way to control the variable of pitch. But the question is should we have gone with something else, because does the keyboard inherently suggest this is really just a different kind of piano, which modified piano. You should approach it like a piano, use it like a piano. You bring your piano playing behaviors to the machine, and they were they were torn on that because they were thinking, well, what if we didn't include the keyboard, might that help encourage people to use this to generate sounds in a way that's truly new and doesn't mimic the way we've used other instruments before. Of course, we know they did end up going with the keyboard, and that kind of makes sense because the keyboard is a very useful and intuitive way to control pitch, but especially when you get to a point where you're capable of producing more than one one tone by pressing more than one key at once, right, some early synthesizers were only capable of performing like you press one key and that's the sound you would get, but you would not be able to create harmonies with some early synthesizers where you know you were if you change from key to key, you change the pitch, but you couldn't hold down a chord and have all three notes play, and some early early synthesizers. I think that's the case with the mog and it I believe so, and that that would mean that you could change out the keyboard for something like a lever. Then you pull the lever, and maybe when you pull the lever in one direction the pitch increases, and when you put push the lever the other direction, the pitch lowers. That could have in the control device or anything else. Really it didn't have to be the keyboard, but they decided ultimately to have the keyboard because again it I think you're right. I think it makes it easier to understand how to produce the sound you want to produce. It becomes less It slightly steps away from the element of performance art the way a theoreman kind of is like, you can get a really skilled theremin player to create particular sounds and even play particular pieces of music, but it is hard. It is is It is an art to learn how to do that, and even then it's very imprecise. I think they probably should have replaced the keyboard with a big, big row of holes filled with a putty like a google that you have to insert your fingers into to play the note. Starting to make me think of like some sort of combination of a musical instrument, and that the Tree of Death and Flash Cordon reach inside and discover the true tones of the future. Right, So, uh, let's talk about waveforms because we mentioned them a little bit with sign waves, square waves, triangle waves, sawtooth waves. What what the heck to all of these mean? Um? And we've already talked about what a waves period is, We've talked about frequency and amplitude and uh. For for a lot of this, I'm going to be looking at using the example of a one hundred hurts um wave or frequency rather one hundred hurts frequency, so that it makes it easy for me to use the math to describe the different wave forms, because if I go with something that's not easy, then I would have to do a whole bunch of different calculations of the So I mentioned earlier, sign waves are that pure wave, is that fundamental frequency? Uh? This would be the same as if you were to take a tuning fork and ring it. It's going to create a true tone with no harmonics. It's a single sound. Uh. And so at one hundred hurts, you would have a wave where it's period is being repeated one hundred times every second, and that's all you would get just that, and it would be at a steady amplitude unless you were adjusting the volume. So again, amplitude refers to how loud it is in this case for for sound. Uh. And also what's really neat is that you know, you we depict this with the the peaks and valleys on a on an X Y axis, whereas the like the x axis the horizontal axis that represents time, and the vertical axis represents the the amplitude the volume. Uh. If you were to match up two sound waves that are identical, but the peaks of one sound wave are matched with the troughs of the other sound wave perfectly, they cancel each other out. So you play these two sounds simultaneously, if they line up in that way, they cancel one another out. It's like it's like all the atoms can't move because they're pushing against each other and not actually creating the vibration required for you to hear a noise. Noise canceling headphones work on a pretty similar principle to this to some degree. So that's kind of interesting. All right, So let's talk about saw tooth waves. If you look at these, it looks like a ramp and then it's like the ramp goes up into the right and then immediately drops off like has a vertical drop, and then moves up into the right again, and that's why it's called saw tooth. It looks like the teeth of a saw blade. Um These when you play them, have a buzzing sound that's really strong and clear. So this is what a saw tooth wave sounds like. Now, those are made by combining a series of sign waves at different frequencies and volume levels. The loudest sign wave defines the frequency of the overall saw tooth wave, and that is the fundamental frequency, and the other sign waves represent the harmonics, which are deally at a frequent that complements the fundamental one. So generally what we talk about are multiples of the fundamental frequency. That's why I'm going to start with a one hurts. So at a hundred hurts, your next multiple like harmonic harmonic. The first harmonic would be number two because number one is your fundamental that's one hurts. Number two would be two hundred hurts because it's the multiple that's the harmonic. Number three is three hurts, four is four hundred hurts, so on and so forth. Multiple and harmonic number are the same thing as what I'm trying to get across. All of those are playing at the same time. But the amplitude of the harmonics is lower than the amplitude of the fundamental frequency, meaning they're quieter, right, They're not overwhelming, Otherwise you would just have noise. So uh, it drops with each step further away from the fundamental frequency, and it stretches on effectively into infinity. Eventually it gets to a point where it's so low that it's impossible for us to understand. So yeah, while the wave effectively or the the harmonics effectively go on into infinity, eventually one you hit a frequency that humans cannot perceive and to its well, in general, humans have trouble perceiving, and it's at an amplitude that's so low that you wouldn't be able to hear it anyway. The volume is too low for you to be able to detect it. But that's the that's what gives the saw tooth wave that tonal character. Then you've got square waves, which look very square. I mean, if you were to look at they almost looked like like the the battlements you might see on the top of a castle wall or something. And uh, square waves contain harmonics like a saw tooth wave, but it only contains the odd numbered harmonics, So you don't have harmonic number two. If you start with one hundred hurts, you wouldn't have two hundred hurts as a harmonic. It would be skipped. But you would have three hundred huh and five hundred and seven hundred and nine hundred. But you skip all the even numbered harmonics. You only include the odd ones. And there's an actual formula for how quiet those harmonics arery What you do is you take the harmonic number and then you do the inversion of that. You invert it. So harmonic three you would invert to one over three or point three three three three, it would have that. That would be its amplitude compared to the fundamental frequency. Five would be one five of the amplitude of the fundamental frequency. Seven would be one seven, etcetera, etcetera, all the way down the line. So a square wave is going to have a a tone that a lot of our listeners are going to recognize because it's the type of wave generated by classic video game console systems like the Nintendo Entertainment System would be a great example. Yeah, so you gotta stop, you gotta stop and tell me what's your favorite in nes eight bit video game music. Uh. I know it's kind of lame to go with such a popular answer, but I really like the Legend of Zelda. That's a great one, you know. I also really I really like Super Mario Brothers. It's great. I really remember liking the music that went with the old ne ne Nes Batman game, which the only movie based games for the NES that wasn't horrible. Yeah, it wasn't wasn't like a just a complete travesty of the franchise rights. It was pretty good game, you know. That's what I'm saying is that that's great music. You remember Do Do Do Do Do? And I never owned it in ne e S, but I have a friend who did, and he had that game, so I do remember that. But anyway, this is what those square wave forms sound like, in case you wanted to know. So, yeah, you could tell. They're a little a little less buzzy than the saw tooth waves. The square ones are slightly less buzzy, but they still have some character to them. And then we have triangle waves. Triangle waves hate person waves. They have a fight triangle wins. Also, they have a really more mellow sound than your square waves or sawtooth waves do, so they kind of sit between square waves and sign waves. They also have harmonics, and they also have only odd numbered harmonics like the square waves do, so just three, five, seven, nine, etcetera. You don't have any even numbered harmonics in the triangle waves. And in this case, the amplitude of the harmonics is the drops off faster than it does with the square waves. So in square remember it's the inversion of the harmonic number, so three is one third, five is one. Five with triangle waves is the inversion of the square of the harmonic. So it's one over three squared or one over nine or point one repeating. So that's it's that amplitude compared to the fundamental frequency. And then etcetera down the road, so it'd be one over five squared, one over seven squared, one over nine squared, etcetera. And that would be your amplitude of your harmonics to the fundamental frequency. Ah, so that that's your basic ones. Oh, in a triangle wave, we should definitely hear what that sounds like. It sounds like this, So those are your basics, like that's you know, those are your the basic qualities of sound you could use. You could you could choose which type of wave you wanted the oscillator to generate with your moge synthesizer, and then put that through the various filters and other modules that we talked about to create all sorts of interesting sounds and and really give your music a very interesting character before you even start playing a melody. So with all of the richness of a variety of electronic music that you can create with synthesizers, I mean, we're focusing on analog synthesizers today, but really with any kind of electronically gym rated in music, there's a lot you can do. Why do why does some people still regard it as fake music? Because some people just I think are narrow minded jerk faces. No, I don't want to, I don't want to really suggest that. I think I think though, this is one of those things that historically we've seen repeated, you know, many times, even before the age of electronic music at all, we saw this, like just with composers styles and you you've heard stories of how after the performance of a particular symphony and audience might riot in reaction because it was so different from what came before it. And I think that's part of it. I think there's some people who just have trouble accepting the idea that something different from what has come before has any can add any value, and if it doesn't fit their definition of what is music, it therefore cannot be music. Um, I don't believe in that. I mean, I will go so far as to say, like, there are there's definitely some experimental music out there that to me sounds indistinguishable from random noise. Like there are some performance aren't pieces, and some of them are meant to be like that, like dropping objects onto piano wires from like twenty feet up so that you could create these these loud noises. It's not like that's done with surgical precision to create a very specific sound, and that's not what the intent of the piece is. Uh, and it it's it gets tricky for me to refer to that as music because it doesn't fit my definition, my personal definition of what music is. So I'm even guilty too of that to some extent. You know, one example I think of that that comes up is, for example, drum machines. Yeah, you hear that criticized all the time. People are like, oh, you know, the music these days, any idiot with the drum machine can just make some loops and then and then there were a musician, and that's not real music, or or people who program music into like it's possible to program music into a computer file without ever touching any kind of musical instrument. Right, You could, in theory, create music just by manipulating numbers if you have a great enough affinity for that. I don't think that makes the music any less valid than anything else. I don't think that there should be a In fact, how different is that from being a composer who creates, who composes music for a symphony and doesn't play it him or herself. Right, Yeah, I would argue that is very similar. And and I also just think that that the creation of music goes beyond how skillful you are at tickling the ivories or being able to plug strings. What did you just say to tickle the ivories? Tickle the ivories? That's playing piano? Where on earth did you learn that expression? What are you? Are you kidding me? Look, tickle them, tickle the ivories? You've never heard this phrase? Are you telling me that? Oh my gosh, well I am older than you are. Uh, tickle the ivories is a phrase that means play the piano. Okay, I guess. I guess I'll just have to go home and beat up my guitar. Well, I'm just saying a phrase that doesn't matter at any rate, Like I don't I don't think. I don't think that musical ability. I'm gonna go roughly chop my drums. I don't think that. Look, I'm about tickling the ivories and you're going into abuse. I don't think of all the bizarre things you can do with your hands that are not playing a musical instrument. Okay, Well that's that's fair. So I'm sorry. Now I'm the one being judgmental. I apologize, Jonathan. I think you should feel free to tickle the ivories however you like, and and I won't judge you for it. I just can't believe you've never heard that phrase before I heard. Well, it's it's pretty common down my way. Um. But at any rate, we had a lot of ivory ticklers when I was growing up. Um. So at the point being that, I don't think that there's any particular skill that you have to possess in order to be someone who makes music other than the ability to create a melody or or you know, to actually create the music in whatever whatever mode you use to do it doesn't matter well, I mean regardless, Like why would we even consider ourselves in the business of certifying what counts as being a musician or not? This? Like, why is that our job to tell people, no, that's not real music. This honestly reminds me a lot of the debate of whether or not video games or art or video games just contain art. So in other words, like, yeah, the graphics in a video game can be considered art, the music accompanying a video game can be considered art. But is a video game itself art? And there's people who very violently say absolutely not, there is no way a video game itself could be art. Do they have some kind of like philosophical principle in forming this opinion? I think they just have some sort of ridiculous narrow definition of what they think art has to fall in. Yeah, so I would say that this that the electronic music has fallen into that same thing that some people. For them, they have a very narrow definition of what music is. An electronic music falls outside of that definition, so therefore it cannot be music by by definition. Problem is that's not everyone's definition. I have a much broader opinion of what is music, maybe not as broad as other people. In fact, certainly not as broad as other people. I know there are folks who like music that I just find uh baffling, like there's no appeal to me. So I know that I'm also guilty of that, but I'm at least aware of it. So that's the story of the Moag synthesizer, what it did, the the actual wave forms that are produced, and how those come together to make various sounds. I gotta thank you, Joe for being on the show and joining me to have this discussion. It's been like you for inviting me. And I have to thank Noel for all the amazing work he will be doing on this episode that I have not yet heard because obviously he'll be adding it in later, but I can't wait. He was very eager to do it, Joe. You know, Noel is like he's crazy talented when it comes to music. Killer He he composed created the new music that the new theme music we have on over on stuff to build your mind, which I much preferred to the old theme music. He also did the music for tech stuff, which I much prefer to the old music. So yeah, Noel is a is a kind of a amazing and he's always working on something. Um Actually, one thing I would love Noel to do at some point, I'll have to do another episode about music so that Nol can play some of his mouth noise symphony for listeners, because he's created musical pieces where all of the all of the sounds come from various mouth noises. They's cut out of podcasts and then manipulated in some way to make the musical and you would not necessarily know that it was a series of mouth sounds if you listen to it without being told first. It's kind of cool as the sort of thing he does him he can really tickle the mouth sound. You really can. I can't believe you're giving me crap about this very valid phrase that when you google it you are going to be shocked that there are other people who have used it. Okay, well, and that we're going to wrap this up. This has been an epic episode about Mode. It's been fun and guys, if you enjoyed this episode, please let us know if you have suggestions for other topics or suggestions for people I should get on the show, either as a guest or an interview subject. I'd love to hear from you. Send me an email that address is tech stuff at how stuff works dot com, or drop me a line on Facebook, Tumbler, or Twitter. To handle it all three, it's tech Stuff hs W, and I'll talk to you again. Really sat. For more on this and bathans of other hathics, visit has stuff works dot com.