Earlier this year Israel unveiled its latest weapon, a device called the Thunder Generator. Designed for crowd control and developed by PDT Agro, a firm that manufactures sonic instruments for scaring birds from crops, the Thunder Generator projects a sonic boom so piercing that it may cause permanent injury or death to anyone within ten meters. The Thunder Generator does not emit music, but the aggressive pitch of its sonic disturbance has a lot in common with military uses of music—and I don’t mean the brassy marches of John Philip Sousa. During the 1989 invasion of Panama, US forces used an ear-splitting barrage of Led Zeppelin and Martha Reeves and the Vandellas to drive Manuel Noriega from his redoubt in the Vatican Embassy. Several years ago in Iraq, during the assault on Falluja, US Marines bombarded insurgents with, among other things, blasts of heavy metal.
What if the Thunder Generator’s booms were made into a beat? How would it sound on a record? Would it be funky? That the Thunder Generator would ever be used to make tail feathers shake is unlikely, but in the history of music there are many cases of invention and accident resulting in the genesis of new sounds. The theremin was the fruit of Soviet government research conducted in the 1920s on proximity sensors, instruments that could gauge the distance of objects without touching them. It was a scientific tool, and when it came to be used musically people thought only to manipulate it to approximate the human voice, or to play mostly classical tunes. Yet even an instrument as marginal as the theremin is known to most of us: it’s the sound of spook in horror movies, the trebly warble in "Good Vibrations."
Somehow more unlikely and yet more influential is the vocoder, whose history is told in Dave Tompkins’s fascinating debut book, How to Wreck a Nice Beach. Developed in the 1920s by Bell Labs as a device for cramming phone conversations into the transatlantic cable, the vocoder was eventually engineered into a tool for encoding and deciphering top-secret military communications. A "massive walk-in closet of cryptology," Tompkins writes, the vocoder divided the human voice into ten constituent frequencies before transmission. The frequencies were scrambled with the aid of a pair of turntables playing sixteen-inch custom-made albums of "thermal noise in reverse, a randomized shush, backwards masked inside out." At the receiving end those ten frequencies were recombined (using an identical set of vinyl records). The turntables had to be synched precisely to the messages. When the message had been decoded and played back through the curiously altered voice of the vocoder, both sets of records were destroyed. The vocoded sound was something resembling the human voice, but in the coding process strange noises crept in, and the sound became a kind of warped version of language.
You have heard the progeny of the vocoder, even if you don’t know what it is. It’s in the processed vocal chorus of Lady Gaga’s dance-pop and the surreptitious pitch correction done in-studio for the latest American Idol winner who can’t quite hit all those notes. Perhaps you’ve heard it in the steely processing on Kraftwerk’s "Autobahn," the spaced-out funk of Afrika Bambaataa’s "Planet Rock" or the buzzy low-rider anthem of Roger Troutman on Zapp’s "More Bounce to the Ounce." Surely you’ve heard the talk box in Peter Frampton’s many megahits and the songs of Jeff Beck and Stevie Wonder. If you haven’t, what the talk box does is broadcast the amplified sound of a guitar or synthesizer into the mouth through a tube clenched tight by the teeth. The musician molds the sound by lip-synching or varying the shape of the mouth and letting it wash over the mic.