Mari Kimura on Subharmonics
The violinist continues to explore the world below G
One day nearly 20 years ago, violinist Mari Kimura was practicing a son filé exercise she’d long used to improve her sound on the E string, and on a lark decided to try it down on her G string. She drew her bow very slowly, and applied a bit more pressure than usual. Suddenly she heard a crunch and a scrape—and a G note a whole octave below what the violin is supposed to be able to play without changing the tuning.
This extended bowing technique, producing what Kimura calls “subharmonics,” wasn’t exactly new; Paganini is thought to have toyed with it during his practice sessions. But with a few exceptions, such as George Crumb’s Black Angels, it wasn’t commonly found in compositions. Kimura, who first described the technique in a 2001 Strings article, resolved to master the technique, stabilize the sound, and use subharmonics in her own music—and encourage other composers to use them, too.
Through practice, Kimura managed to eliminate most of the scratchy transient noise associated with the technique, and she incorporated subharmonics into a recital she gave in 1994. Since then, she’s been refining the technique. By carefully controlling the location, speed, and pressure of the bow on the string, she can play almost all the chromatic intervals below the string’s fundamental notes. When she plays the open G, she can produce the G an octave below; when she plays middle C on the G string—by pressing the string down to the fingerboard normally, not barely touching it as with “regular” harmonics—she can produce the viola’s open C. On the open G string, she can also get minor seconds, minor thirds and, she says, “on a good day,” a perfect fifth.
Still, not all the notes are stable, even on the best string for the purpose, the G. (Subharmonics are possible on the higher strings, but the sound isn’t so good.)
“The hard part is to play reliably on cue,” she says. “Anybody can do this by accident, but not necessarily on demand. It takes a lot of control of my right arm, as well as mental preparation.
“When I first started I thought it was all in my head: when I believed I could play it, I could play it, but when I had doubts, I couldn’t. It’s like ‘the force is with you.’ But that’s not good enough for a performance. I have to keep a kinetic memory of my right arm where that vibration locks in—one way to play the octave, another way to play the third. The fifth comes only on a very, very good day.”
In performance, Kimura says, “That’s not good enough for me to use.”
Even with the notes solidly in her arsenal, Kimura can’t really play a full line using subharmonics. She can play a few notes in succession, but only so long as the single stroke continues. And she can’t play them reliably with the upper bow because, like most string players, she has better control at the frog.
“I can sustain about three seconds worth of stroke for this,” she says, “and that’s enough to play a trill.”
Scientists aren’t quite sure how subharmonics work, aside from the octave effect. To help understand the phenomenon, Kimura recently visited Stanford University’s Max Mathews, a pioneer in the world of computer music who is devising a special microphone to measure subharmonic vibrations and help analyze the effect. Kimura looks forward to learning the results of Mathews’ study.
Meanwhile, she has mastered sufficient “good enough” notes to incorporate them into an entire CD’s worth of original compositions using subharmonics. The self-produced disc, The World Below G, includes Kimura’s Six Caprices for Subharmonics, a three-movement solo suite called Alt, and two versions (one with interactive electronics) of a piece titled Gemini. Subharmonics also abound on her most recent CD, Polytopia (Bridge 9236), a collection of violin-and-electronics pieces by Kimura and six other composers.