The Electric Duet
By Fenella Saunders
Christopher Raphael, an applied mathematician and
professional oboist, found a novel solution to a problem many
musicians face when they rehearse at home. If he wanted to
practice an oboe solo that will be accompanied by a piano, for
instance, he might play along with a recording of the piano
part-but a recording is a sterile and unyielding partner. "That is
the antithesis of what it's supposed to be," he says. So Raphael,
who is at the University of Massachusetts at Amherst, melded
his talents to create a musical computer program that can listen
and adapt its accompaniment to him.
The program, called Music++, picks up the solo through the
small microphone built into most laptops or desktop
computers, and learns to recognize notes from a particular
instrument using the same kind of processing techniques as in
speech recognition software. It also has an adaptive element
that allows it to learn a piece of music and the soloist's playing
style. After several practice sessions, the program can make
real-time decisions to change its interpretation of the
accompanying part, for instance by adapting the speed and
spacing, even if the soloist changes tempo on the fly or makes a
mistake. "The model understands both that musical
performances are highly variable, while there are certain
tendencies that appear from performance to performance,"
Raphael says. There are other musical accompaniment
programs out there, he says, but they do not learn and adapt in
the same way as Music++.
Raphael's main goal for the program is to give musicians a 21st
century tool to aid in their development. "Musicians spend the
majority of their practice time alone," he says. "This makes it
more involved and helps prepare the musician for group
playing." Although he has no desire to take the human
musician out of the mix, he does think that the program might
also help to advance machine learning. "What's really hard for
the computer is getting the expressive component of music," he
says. "Here, it can learn this from actual examples."
- Posted 9/17/02
RELATED WEB SITES:
"Making the Computer 'listen' to Music." Christopher S.
Raphael, Journal of the Acoustical Society of America, Vol.
111, No 5, Pt 2, May 2002.
"The Computer as Musical Accompanist" by Christopher
Raphael can be found at
Hear examples of Raphael's program accompanying his oboe