Sonic Generator. At Georgia Tech, Feb. 12.

Georgia Tech's Sonic Generator ensemble, a sort of workshop for graduate students in Tech's Music Technology program, has become a "helluva, helluva" popular group, drawing an intriguing mix of serious music fans and earnest students.

A program of six pieces performed Tuesday at Tech featured the premiere of "Kaleidoscope I" by Atlanta composer Chris Arrell. A series of short musical figures build up and alternate repetitively, constantly mutating. As the piece moves quickly forward, the colors of the melodic material become richer and are played against each other, resulting in something that is both sensuous and dissonant. It's a skillful exploration of change over time when things are happening fast, like minimalism on amphetamines.

In Jonathan Harvey's "Tombeau de Messiaen," a piano plays a duet with a piano on tape, the instruments tuned differently. As they are played, the piano and its ghost create a torrent of sounds, seeming almost to make the room shake from the violence of the tonal imbalance. (Sonic Generator's pianist is the ubiquitous Lisa Leong. She is in her element with the most difficult and dissonant material.)