Learning music theory with Auto-Tune

Auto-Tune makes producing music easier. It can also make understanding music theory easier. The way you dial up different keys and scales doesn’t just guide your ear, it also guides your eye.

Auto-tune

Your voice can produce a smooth continuum of pitches. To sing, you eliminate most of those possibilities, vibrating your mouth and throat only at certain frequencies, the pitches of the melody. Auto-Tune helps by shifting the voice’s frequency to the closest desired piano-key pitch.

Towards the bottom left is a knob labeled Retune Speed. Even the best singers waver around their intended pitch for a few milliseconds before converging on it. If you correct away that wavering, the result sounds artificial. So Auto-tune can be set to delay its effects. Slower retune speeds allow more human-sounding shakiness to pass through the filter. If you set the retune speed to zero, there’s no wavering allowed, and you get the robo-vocal sound beloved by T-Pain, Kanye West and Lil Wayne. It’s more widely known as the Cher Effect, because a lot of people first encountered it in her song “Believe.” There’s a persistent and false story that Cher used a vocoder for “Believe.” The producers lied in interviews, not wanting to give away their trade secret. Auto-Tune isn’t exactly a software vocoder, but it’s based on the same math.

Music-theoretically, the interesting part of Auto-Tune is the center of the window, listing the twelve pitches on a piano. By default, Auto-Tune is set to the chromatic scale, all the piano keys, starting on C. To Auto-Tune yourself in C major, you need to remove C-sharp, D-sharp, F-sharp, G-sharp and A-sharp. (There are no flats for some reason.) This is a lot like the way you set up a xylophone or marimba for a beginner. By taking the bars for the undesired notes off, you make it impossible to play anything wrong.

A bit of fun for music nerds: the notes you omit from the C major scale, the black keys on the piano, form the F-sharp major pentatonic and E-flat minor pentatonic scales.

To make the C natural minor scale,  you omit C sharp, E, F-sharp, A and B. To get the other minor scales, you’d just need to toggle the sixth and seventh notes differently. For C dorian you’d leave A in and remove G-sharp.

“A Love Supreme” by John Coltrane starts with this a fanfare on the notes B, E and F-sharp.

In the key of C, the fanfare’s three pitches are C, F and G. This is one of my favorite Auto-Tune settings. It sounds amazing on speech.

It’s even more fun to strip the pitch set down even further, taking out the F and even the G for maximum posthuman warbling. Being limited to a smaller group of pitches forces you to concentrate on rhythmic patterns. Check out how cool it sounds when you set Auto-Tune to just the root note.

Auto-Tune’s binary representation of the combinational possibilities of music theory is similar to the way I learned how to conceive my chords and scales in jazz training. You can derive any scale or chord by starting with the chromatic scale and omitting the wrong notes.

Sometimes you want to be constrained to a traditional scale, but more often the blend of pitches you want is more idiosyncratic. In major keys, you very often want to use the minor third and sometimes minor sixth. For a blues feel in any key, you can include the flat fifth. Omitting the fourth and seventh from a major or minor scale makes a dissonance-free pentatonic.

Here’s how you can build your own scales, chords and pitch groups in the key of C, in or out of Auto-Tune.

C: The root or tonic. Probably leave it on.

C-sharp: The flat second. Leave on for Middle Eastern music, turn off for Western.

D: Second. Usually leave on, except for Middle Eastern music.

D-sharp: Minor third. Leave on for tragedy and blues.

E: Major third. Leave on for happy, turn off for sad.

F: Fourth. Probably leave on unless you’re making major pentatonic.

F-sharp: Flat fifth, sharp fourth. Leave on for blues and exotica.

G: Fifth. Probably leave on, though try turning it off for fun.

G-sharp: Minor sixth. Leave on for tragic feel.

A: Major sixth. Leave on for bright/happy feel.

A-sharp: Minor seventh. Leave on for blues, minor, rock, or mixolydian.

B: Major seventh. Leave on for major and harmonic minor, brightness, and suspense.

See more scales in Auto-Tune-like representation.

Symmetry and patterns register on the ears and eyes differently, but there’s substantial and intriguing overlap. If you illuminate every other note on the list, you get the whole tone scale. If you alternate skipping a note, not skipping the next one, skipping the one after that and so on, you get the diminished scale. The symmetries of those scales announce themselves to the ear immediately, though you may not be able to figure out what specifically the symmetries are.

I’m pretty psyched about the convergence of the mind’s eye and the mind’s ear. All digital music-making tools have a synaesthetic element. For visual thinkers like me, the computer’s music visualization tools have opened up some big new swaths of sonic terrain.

Any interesting related music visualization systems out there? Hit me in the comments.

7 thoughts on “Learning music theory with Auto-Tune

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  2. Thanks. I didn’t know about the polyphony point. I was thinking about the subject because I’m a fan of Imogen Heap, and there is a DVD interview with her in the latest issue of FutureMusic magazine UK edition (not sure if you can get this where you are). She is discussing how she processed a trumpet passage played by Arve Henriksen, when she whispers to the camera something like ‘that’s Autotuned, but don’t tell anyone because he doesn’t need it’! And that set me wondering what instruments you could use Autotune on. As you point out, you wouldn’t need to do it with a synthesised or sampled sound, but it could be very useful for natural instruments that go out of tune easily or are difficult to retune, and the piano is a prime example of that.

  3. Hi, I found your page when I searched for ‘autotune piano’. I wanted to find out if it is possible to use autotune on the notes of a piano. Pianos notoriously go out of tune (weather conditions, etc) and it is laborious to tune them, so it would be convenient to be able to ‘correct’ a slightly out-of-tune piano by feeding the sound through autotune. (Of course the notes would have to be correct to the nearest semitone.) I know that autotune can be used on instruments as well as voices, but I don’t know if it would work specifically for the piano without seriously distorting the timbre and the initial ‘attack’ of the notes. Any advice? I’m not planning to do it myself, I’m just curious.

    • Autotune would work great on piano, but there’s a catch: it was designed for voice and it can only handle monophonic sounds. So if you were playing one note at a time, you’d be in business. The new version of Melodyne can handle polyphony and could probably do what you’re describing, though I haven’t yet tried it myself. Auto-tune only colors the tone noticeably when used in extreme ways like the hip-hop guys and Melodyne is quite transparent as well. I do my piano with fake sampled ones, much simpler. :)

  4. My fondest wish for technology is that it puts the fun back in music theory where it belongs. Glad you’re enjoying the post, and the track.

  5. Really interesting post. Back in college 5 years ago I was using free and pirated software make rap beats and teaching myself about music theory in the process, but I never really understood scales (I didn’t have any musical training). If I’d read this blog post 5 years ago and had Autotune I probably would have been really inspired to mess around and teach myself a lot more about scales and chords.

    I really liked the third autotuned track you posted back on http://www.ethanhein.com/wp/2008/in-praise-of-autotune/

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