Kanye West, pitch, tuning and harmony
A chapter of Cold Technology, Hot Beats
Producing exact pitches has historically been a difficult feat. Technology has made it trivially easy, enabling us to explore ever-more complex combinations of frequencies.
Harmonics and harmony
All pitched musical instruments include harmonic oscillators. Their vibrations are a complex sum of different sine waves added together. When sine wave’s frequency is an integer multiple of the fundamental frequency, you hear an agreeable musical tone. The partial vibrations are called overtones, and their study is crucial not just to music theory, but to quantum mechanics, electricity and magnetism, signal processing and many other areas of mathematical science.
People have known since ancient times that when you play the pitches from the overtone series in combination, they sound good together. The musical intervals are simple ratios of different frequencies combined together. Most people find ratios of simple counting numbers more pleasant to the ear than complex ratios. We hear the octave (one to two) to be a nicer sound than the tritone (one to the square root of two.)
Tuning systems are like the rules of a game. You’re free to bend or even break the rules, as long as you do it in a patterned and systematic way that gives the listener’s ears time to adjust. Every time an electric guitarist bends a string or hits the whammy bar, it produces microtones, pitches in between the piano keys. This kind of complexity works best over repetitive forms like blues and rock.
Keyboards and frets
The pitch spectrum you can make with your voice is continuous. It’s hard to sing a perfect C. The frets on a guitar make it easier to reproduce particular pitches, which is especially important if you want to play good-sounding chords with five or six different notes in them. Keyboard instruments make it even easier to produce any desired combination of pitches.
Technology makes concepts that are hard on the brain fall easily under the fingers, like the Hendrix chord.
To keep your instruments in tune, you need an accurate reference pitch. In the electronic era, we use vibrating quartz crystals, which are superbly accurate and extremely cheap. Before electronics, people used tuning forks, pieces of metal of the right size, shape and composition to vibrate in a predictable way. If you hook up tuning forks to magnetic pickups, you can make an electric piano.
Electronic tuning and harmony
You can experiment with analog pitch shifting by changing the speed of a record or tape player. If the recording plays slower, its pitch gets lower, and if it plays faster the pitch goes higher. Computers can decouple pitch from tempo, so it’s possible to change a recording’s pitch without affecting its speed, and vice versa.
In the seventies people started using the vocoder to map their voices to specific pitches using synthesizers, and to create science fiction flavored artificial harmonies. The robotic speech by Herbie Hancock and Fab Five Freddy in “Rockit” was processed through a vocoder.
Computers have opened up new avenues of harmonic expression. Software like Auto-tune was intended to correct sloppy vocal performances. As with most music tools, though, musicians and producers have found uses for Auto-tune that go far beyond the designer’s intentions. Excessive Auto-tune gives a singer’s pitch an unearthly perfection. Producers can also use it to find melodies in unpitched speech.
The sound of extreme Auto-tune has become ubiquitous in pop music, especially hip-hop and R&B as practiced by T-Pain, Lil Wayne and Kanye West.
Auto-tune may be on the verge of transforming karaoke as well, now that there’s a version of it for the iPhone. If anyone can sing perfectly in tune at will, what does that mean for the authenticity of music? This question causes many musicians and fans considerable vexation. The freedom and flexibility of artificial harmony opens up a lot of new creative doors, and the inclusiveness the software creates is all for the best.
Playlist
JS Bach – “The Well-Tempered Clavier”
Thelonious Monk – “Ask Me Now”
Daft Punk – “Harder, Better, Faster, Stronger”
