At its core, music is nothing more than a data stream. It's the result of oscillations in frequency and volume of soundwaves produced by an instrument that, when played by the right person, sounds pretty. As we've gained a better understanding of how sound works and how to manipulte those oscillations, we've been able to create new instruments from the motion-controlled theramin to the digitally driven synthesizer. And using the same sort of sonification techniques—sonification is simply the process of translating information into sound—scientists are perfecting another musical instrument: the human brain.
Katinka Kleijn is a classical musician in every sense. An accomplished cellist and a longtime member of the Chicago Symphony Orchestra, she's been branching out lately and exploring new technologies for making music. Last weekend, she took her latest fascination, brainwave-powered music, public in a concert where she played a duet with herself. One part was for the cello, and the other was for her brain.
To turn her brainwaves into sounds, Kleijn wore an Emotiv EPOC neuroheadset that uses 14 sensors attached to the scalp to read brainwaves. She hacked the headset with the help of a sound engineer and a composer so that it would translate the brainwaves into sounds and kept a laptop on stage with her that would display different words while she was playing. The changes in her thoughts as she cycled through the words made the music. The piece is called Intelligence in the Human-Machine.
"Not only is Katinka playing the cello, but she is also, in a sense, playing her brain waves, emphasizing what’s going on in her brain while she’s performing," composer Daniel Deehan explained to Time after the concert. "She might have a very peaceful melody, but she’s received the word violent, so through this peaceful melody, she has to emote violence." Deehan walked through the technical details in a separate interview with the Chicago Reader. "The brain fires electrical impulses, but at rates well below what we can hear — and on top of that there's a ton of noise from muscles and the air that's part of the stream," Dehaan said. "The first thing I did was to record it as raw data — which is just a bunch of pips and pops — and then shift it up into the audible range and manipulate the playback rate."
Kleijn is hardly the first person to turn brainwaves into music. Back in 1965, American composer Alvin Lucier created Music for a Solo Performer, which pumped alpha waves produced by the brain through an oscillator and then through speakers. The vibrations created by the sounds rattled nearby percussion instruments.
Similar techniques have since been used by David Rosenboom, Richard Teitelbaum, and Masaki Batoh of Japanese rock band Ghost. Kleijn's recent performance was nearly three years in the making and started out as an attempt to translate lie detector data into sound.
You can listen to the end result in the video below. It does not sound like Bach, but that's sort of the point. "We're trying to shed light or bring sound to this interaction between external and performer," said Dehaan before the performance. "We'll be hearing not only Katinka trying to express [things] musically, but also the result of her brain state in trying to achieve that — or her initial reaction while being in a moment of, say, tranquility, and then one of destruction."
Image via Flickr