How does a synthesizer shape soundwaves to emulate the sounds of bells or helicopters or organs? Pandora's Music Operations Manager Steve Hogan joins host Kevin Seal to look at how a basic square wave or sine wave can twist and morph. They break down the Attack-Decay-Sustain-Release model of synthesis, and show how to sculpt some sounds that go from beeping to birdsong, and from white noise to whistling. (10 mins.)
Click the "Continue reading" button below to see the shapes of the actual soundwaves, and to hear clips of analog synths being used in everything from the Monkees to Kraftwerk to the Killers and the Rapture to Dr. Dre's productions.
 |
Steve's left hand is on the Modulation Wheel. This wheel is assignable to control nearly every function; in this episode, Steve sets it to control the pitch of the second oscillator. |
MUSICAL TERMS INCLUDED IN THIS PODCAST
| Square wave | Attack (A) | Synthesis | FM Synthesis |
| Sine wave | Decay (D) | Fundamental | Operator |
| Sawtooth wave | Sustain (S) | Overtone | Portamento |
| Triangle wave | Release (R) | Algorithm | Resonance |
| Waveform | ADSR amplitude envelope | Emulation | Low-pass filter |
| Wave cycle | Amplitude | Oscillator | Band-pass filter |
 |
The fundamental tone is a signal's basic unadorned tone, with zero overtones. A pure sine wave is nothing but the fundmental tone at a given frequency (e.g. 440 Hz or 20 Hz or 7000 Hz). When overtones are added to the fundamental, the waves interfere with one another and distort the waveform. In this example, when the third harmonic is added as an overtone, the sine wave begins to resemble a triangle wave. Generally, when you have multiple waves happening simultaneously, they interfere with one another, both constructively and destructively. This interference is harmonic distortion. |
EARLY SYNTHETIC TONE MANIPULATION
by Herbert Eimert (1952) |
|
by Louis & Bebe Barron (1956) |
|
by Edgard Varese (1958) |
|
by Dick Raaijmakers (1959) |
|
by Herbert Brun (1962) |
 |
Here are some different varieties of waveforms. These waveforms demonstrate how each of these signals shows up when viewed through a spectrum analyzer. The sine wave, second from top, has no overtones. The square wave, third from bottom, has a substantial number of overtone waves interfering. Each right angle of a square wave is actually many round sine waves interfering with one another. The "ramp up" and "ramp down" illustrations shown here are different kinds of sawtooth waves. |
THE ANALOG SYNTH'S POP DEBUT IN LATE-1960s PSYCHEDELIA
by the Monkees (1967) |
|
by Tangerine Dream (1967) |
|
by the Silver Apples (1968) |
|
by Pink Floyd (1969) |
|
by the Beatles (1969) |
 |
The number of wave cycles per second is that signal's frequency, and is measured in Hertz, abbreviated as Hz. The frequency of a wave creates its pitch. The A above middle C on a piano, for example, is 440 Hz (440 wave cycles per second). That A is the often-cited reference point for ensuring "A-440 tuning." One octave above that A is double the frequency, and is 880 Hz. The next A, another octave higher, doubles that frequency, and is 1760 Hz. |
THE MINI-MOOG AND OTHER MONOPHONIC SYNTHS IN THE 1970s
by Emerson, Lake & Palmer (Keith Emerson, 1972) |
|
by Rick Wakeman (1973) |
|
by the Strawbs (John Hawken, 1974) |
|
by Pink Floyd (Rick Wright, 1975) |
|
by Genesis (Tony Banks on an ARP Pro-Soloist, 1978) |
|
by the Cars (Greg Hawkes, 1978) |
|
by Pendragon (Clive Nolan, and yes, this one is early '80s) |
 |
With each of these graphs, the y-axis represents air pressure, and the x-axis represents time. As the signal continues over time, it varies the transmission of air pressure (therefore, the displacement of air emits a sound). The area of each wave above the x-axis is measured to be that wave's amplitude. |
KRAFTWERK AND THEIR GERMAN RELATIVES -- SYNTHETIC ROBOT POP
by Faust (1972) |
|
by Neu! (1972) |
|
by Kraftwerk (1974) |
|
by Klaus Schulze (1975) |
|
by Can (1975) |
|
by Jean Michel Jarre (1977; French, not German) |
 |
As Steve applies filters to the signal, parts of the frequency range are removed. This process could be compared with whittling a piece of wood, or chipping away at a chunk of marble. Low pass filters (left) remove the higher frequencies, allowing only the lower frequencies to pass through. A band pass filter (upper right) allows only a certain limited range of frequencies to remain. As Steve twists the knob on the band pass filter, that range of frequencies moves (e.g. from 20Hz-2KHz up to 5KHz-10KHz and higher). |
SYNTHESIZERS IN DR. DRE'S HIP-HOP PRODUCTIONS
by World Class Wreckin' Cru (1988) |
|
by J.J. Fad (1988) |
|
by the D.O.C. (1989) |
|
by Michel'le (1989) |
|
by Blackstreet (1996) |
 |
Here are the knobs (or dials) that control Cutoff and Resonance. Steve can assign these knobs to control the low pass or band pass filter. With these, Steve is able to make the filter sweep mentioned above, in which different frequencies are allowed to pass through and remain, as other frequencies are filtered out of the signal. |
MODERN MANIPULATORS -- CONTEMPORARY WAVE-TWISTING
by Money Mark (2001) |
|
by the Beastie Boys (2004) |
|
by John Frusciante (2004) |
|
by Omar A. Rodriguez-Lopez (2004) |
|
by the Killers (2006) |
|
by Thom Yorke (2006) |
|
by the Rapture (2006) |
|
by Stereolab (2006) |
 |
That tube in front of Steve's mouth controls the vocoder function. As he moves his mouth to speak, the shapes formed by his mouth change the synthesizer's signal, and in this way the synthesizer imitates the human voice. To hear more about the vocoder, check out Ariah Firefly in the "Mixing Vocals" episode of the Pandora Podcast Series. |
Darian Gray, drummer and rapper from 
The herbivores and carnivores were waiting outside my door...
The warped wave-twisting microedits of artists like 
If you are familiar with the films of Woody Allen, you've heard examples of gypsy jazz. Pandora engineer and lead guitarist Vic Wong brings in other hot club players to demonstrate how gypsy jazz is played.
Guitarist Russell Johnson talks with us about the history of dissonance in art music, and the rise of atonality in classical composition.
Why does it sound more like Britpop when you play hi-hat with two hands, and more like American rock when played with one hand?
Melody Parker sings and speaks about building melodic lines, from the broad leaps of 
Leather, spikes and blood, as we dive into the diversely metallic styles of 
Check out how songs can shift from 4/4 into 12/8 and more, using parts of the beat to pivot.
From the drummer's British-style swing to the method they used to alter the piano's tone with a tissue box, we hear how "You Gave Me This" was constructed, layer by layer.
Alan Lin and Yair Evnine pull back the curtains on string playing and the emotional impact of strings -- the bow and the pluck, the double-stops and more.
This shows you which episodes talk about which aspects of music -- a handy little reference page for all y'all.
Time to warm up your mouthpieces, empty your spit valves, and get your brass going.
Greg and Kelly from 
Guitarist Bob Coons breaks out the fluid bends, blue notes and heptonic scales that great blues musicians from 
Why are so many Christmas songs swung? What are the stories behind the origin of these classic songs?
A look at great lyrics and the imagery in the words of Leonard Cohen, Joni Mitchell, Elvis Costello, Eminem and others.
A pocket guide for sight-singing, with well-known melodies that will help you hit sixths, tritones, and other tricky leaps.
Producers from 
Marimba man Matt Cannon gets into soft and loud dynamics, using songs by Sinead O'Connor, Shirley Bassey and others.
Hip-hop history in ten minutes, from the lengthy phrases of 
Guitar heroes all have signature riff styles: 
Global rhythms have more in common than in difference, from Indian tabla to Indonesian gamelan and Brazilian samba drums. We hear how they can fit together.
When that singer's voice grabs you by the throat, you know it's been mixed right. Explore what the studio experts do to make it happen.
It's the yin and yang. The 
When he's not touring with 
A modern history of Jamaican music, from 
Explore the ways that composers from 
Breaking down the different percussive patterns played in mambo and salsa, and a look at the music's Cuban roots in cha and son.
See what a great singer does in the studio to make sure her vocal tracks hit just right.
Many guitarists have used effects to great (ahem) effect: 
How a basic backbeat can go from disco to hard rock with the subtlest of changes.
Singing in combination was central to the sound of the Beatles, the Beach Boys, the Temptations, R.E.M. and ABBA -- this show is all about harmonizing.
Comments
heh you folks are really taking me back.. around 1980 when I was at a summer session of college I took (as a lark) an electronic music class... one of the more fun things I ever got a chance to do when at school. We had some decent gear, a moog (same one used to do Close Encounters) and an Emu.. I had a lot of fun creating sounds much like you described in this podcast..
One of the more unique things I was able to do was make a very passable imitation of wind in a storm, gusting... feeding an LFO back into itself so that its amplitude controls its pitch, and you get something that 'gusts' in the sense that as it starts to build it builds faster, comes rapidly to a peak and then slows down as it goes away ... fire up a couple of those and you get a very random series of gusts.. Then using that to control filters and white noise.. after a little work I had a great imitation of a windstorm..
Yeah the class was electronic music, but I spent all my time making sounds and sound effects.. Still gave me a great appreciation for what is possible with a synth.. and also a better appreciation for synth artists who don't use it as 'just another keyboard' (picking from premade sounds).. but actually get into the waveforms, lfo's, filters, envelope and such to create their own sounds..
Posted by: cernenus at August 17, 2007 03:42 PM
Oh one other quick question/comment. Where would you classify the group Synergy in your sample groupings?
Posted by: cernenus at August 17, 2007 04:01 PM
Windstorms on old analog synths are fantastic. I used to do that with DX7s back in the 80s. Way fun, too.
Synergy, eh? I'm afraid to say that I've never heard Synergy... or if I have I wasn't aware of who it was. I'll make a Synergy station and get back to you on that.
Posted by: Kevin Seal at August 17, 2007 07:51 PM
Wow! Larry Fast, eh? I loved his synthesizer work on those Peter Gabriel records, but had no idea that he also recorded as Synergy. Very cool stuff -- thanks for turning me on to it, Cernenus.
I'd probably put Synergy in there with ELP, Genesis, Pink Floyd and other progressive rock. ("Monophonic Synths In The 1970s.")
Where would you put them/him?
(My new Synergy Radio station:
http://www.pandora.com/stations/a459ea7423a4c26a292e04b8cd2aff7f7b1060da19ff9c7a )
Posted by: Kevin Seal at August 17, 2007 08:11 PM
I noticed that the new sound Steve is working on sounds similar to the synthesis in Daft Punk's Something About Us at first; sexy and mellow.
Posted by: Wilson at August 17, 2007 11:42 PM
Awesome. I love Daft Punk. Yeah, I can hear that similarity. Thanks for listening, Wilson.
Posted by: Kevin Seal at August 18, 2007 02:24 PM
I really liked this episode!! Can I download the record of where Steve was playing along with Jeff Anthony's track?
Posted by: Chris Miller at August 19, 2007 08:28 PM
yay! I've loved this episode, and I'm also loving that I've just obtained a microkorg like the one used for this examples, unfortunately I'm not that talented designing sounds... yet.
Posted by: sosa at August 20, 2007 01:52 PM
Very cool! Synths really make the physics of music very apparent, and as a physics teacher and music fan I like that. If people want to play with sine waves, there's a great applet at http://www.falstad.com/fourier/. He's written another to demonstrate filters that's also fun.
Posted by: Jeff at August 20, 2007 02:37 PM
Sosa,
Well, our intention was not to be an advertisement for the MicroKorg, but it's a sweet synth! There is a learning curve, but you'll be making cool sounds in no time - just start twisting those knobs... The key is learing how to take advantage of the 4 'patches' - that's where you can assign the LFO's to control a bunch of different aspects of the sound (filters, volume, pitch...).
Have fun with it!
Posted by: Steve at August 21, 2007 01:51 PM
Luvvin this podcast fellas!
Wish I had this 5 years ago when I was teaching myself all these little details!!!
Posted by: Chris Horgan at August 22, 2007 04:51 PM
this was a fun refresher course for me. i've been away from making music for awhile, but i've been wanting to get back to producing.
is there any chance we'll see more of this, maybe some more advanced synthesis?
Posted by: jonathan claydon at August 28, 2007 02:52 PM
Jonathan,
Yeah - Kevin and I were talking about doing a couple more & getting into some other synthesis concepts. Like maybe trying to dissect some famous synth sounds.
Any topics come to mind you'd like us to cover?
Thanks for listening!
Posted by: Steve Hogan at August 29, 2007 02:30 PM
Finally go to listen to l8 & l9. l8 was cool and I loved l9 all of the first group samples and a couple of the 2nd were my favs. Guess it magically fixed itself.
Posted by: Sunshine/Rainbow at September 24, 2007 03:52 PM
Thanks, guys! And yes, please, bring on the suggestions for what you'd like to hear. We are, as always, all ears.
Posted by: Kevin Seal at September 27, 2007 05:53 PM
wonderful
that's ture
Thi is a nice pag...
Posted by: san at March 31, 2008 11:56 PM
yay! I've loved this episode, and I'm also loving that I've just obtained a microkorg like the one used for this examples, unfortunately I'm not that talented designing sounds... yet
THANKS
Posted by: مسجات at May 5, 2008 06:41 AM
WHYYY is Peter Frampton not on here!?
Posted by: Jackie at June 3, 2008 04:52 PM
the sythesizer used in close encounters was not a moog but an ARP and the person using it was an engineer of the company
Posted by: lawrence lowell at August 11, 2008 01:38 PM
That is correct, Lawrence -- thanks. We didn't make any mention of Close Encounters, did we?
Posted by: Kevin Seal at August 11, 2008 01:47 PM
Post a comment