The American Camerata for New Music did something at its concert at American University's New Lecture Hall last night that the other groups around town which specialize in contemporary music ought to note and emulate. Afer a sharp-witted performance of Schoenberg's brief and little known "There Pieces for Chamber Orchestra," conductor John Stephens announced that the group would play the pieces again.

What a difference it made the second time through! Having allowed the music to define itself on first hearing one could listen again with a sense of context and informed expectations. The music's sense could be savored.

The program itself had a marvelous variety without seeming at all scattered.

The most fun came with a work for tape and percussion called "Everlivin' Rhythm" by Neil Rolnick. The computer-generated sounds on the tape were integrated expertly with the whole smorgasbord of percussion stuff, and provided, at times, almost a chaconne-like structure. Soloist Thomas Jones was almost as much fun to watch as to listen to, and the whole thing was a delight.

Had the acoustics of the room been better, the Harpsichord Concerto by De Falla would have been more effective. As it was, harpsichordist Russell Woollen's virtuosity was swallowed up in the sounds of the other instruments and never was able to assert itself.

The concert ended with a clearly delineated performance of Hindemith's dry and intricate Octet.