Not too many years ago, it would have been impossible for a brass ensemble to present a concert as stimulating and varied as the one given by the American Brass Quintet Saturday night at the Terrace Theater. Until recently, the repertoire for brass chamber groups was so heavily weighted toward early music that players often had to balance masterpieces with transcriptions, often unconvincing, of later music. The emergence of virtuoso brass ensembles has changed that, as contemporary composers have produced music to challenge the amazing techniques of these groups.

Although Venetian canzoni and Elizabethan consort music were well represented Saturday, the quintet gave equal attention to the 20th century with stunning performances of new works, some written for them. David Snow's "Dance Movements," inspired by Stravinsky's late ballet, paid its dues to that score by quoting its opening fanfare and then proceeded to choreograph the sound of paired trumpets and trombones into wonderfully kinetic and fluid antiphonal configurations.

J.S. Bach fared a bit less well. His final work, "The Art of Fugue," is written in open score and is thus fair game for any kind of transcription. Contrapunctus 3 was beautiful and projected real grandeur, but the Contrapunctus 9 double fugue sounded wrong. Its fast and long-lined first subject was clearly not conceived with the bass trombone in mind, and even the technical sorcery of bass trombonist Robert Biddlecome couldn't carry it.

William Lovelock's "Suite," written for the American Brass Quintet, was less adventuresome than the Snow work, but full of acrobatic writing. Its Toccata movement was indeed a showpiece for the virtuosity of trumpeters Raymond Mase and Chris Gekker.