Paul Zukofsky, violin; Robert Sylvester, cello; David Gilbert, Thomas Nyfenger, Harvey Sollberger, Sophie Sollberger, flutes; Stuart Dempster, Lawrence Dwyer, Frank Harmantas, Lynn Newton, Paul Vander Gheynst, trombones; The Group for Contemporary Music at Columbia University, Harvey Sollberger conducting; Robert DiDomenica, flute and piccolo; Peter Bowman, oboe; William Wrzesien, clarinet; Max Winder, violin; Bernard Kadinoff, viola; Stephen Geber, cello; Charles Kiefer, tape; David Epstein conducting.

From refined formality to unpredictable unruliness, the character of the pieces in this recording illustrates the wide range of expression in American concert music of the 1960s. An emphasis on timbre and texture, a rigorous sense of form, and a demand for performer virtuosity characterize all five of these works. Otherwise, they explore strikingly diverse terrains.

Phillip Rhodes's Duo for Violin and Cello is an exploration of timbral eccentricities and special effects. It is nontonal, compact, and sharply focused-at least in its opening sections. Fierce accretions of energy followed by sudden disintegrations constitute the basic drama in the piece before its drift toward a more lyrical discourse and a serene close.

Harvey Sollberger invests his brief but multi-layered Grand Quartet (1962) with all manner of adventurous as well as traditional flute devices, including piercing trills, long chords, sudden melodic leaps, and rapidly alternating single notes.

A dramatic contrast to both works is the wildly expressionistic Ricercar a 5 for Trombones, written in 1966 by Robert Erickson. As its title indicates, this work, written for Stuart Dempster (who is part of the trombone quintet in this recording), uses Baroque imitation among its five voices. It is a sonic adventure that revs up like multiple motorcycles-spitting, growling, whining, and finally, whispering. The five trombonists are required to sing, whistle, and bang as they play punishing fanfares, slides, and other devices. Erickson's dark, multilayered polyphony conveys a powerful sense of mystery similar to the soundworld of Ligeti or Xenakis. This piece is avant-garde in the old sense-tough and challenging, but mischievous and fun.

A more delicate aesthetic whispers through Peter Westergaard's 1963 Variations for Six Players－clarity of texture and structure and a refined timbral sensibility that imparts a beautiful sheen to his music.

Edwin Dugger's 1966 Music for Synthesizer and Six Instruments represents another development of the sixties avant-garde －experimentation with electronic sound to extend the tonal palette and create different sounds.