On Friday night, at Sweeney Concert Hall, at Smith College, the Trio of Peter Brötzmann on reeds and saxophones, William Parker on bass, stringed instruments and flutes, and Hamid Drake on trap set and frame drum, cut through the architectural formality of the hall and broadcast acoustically alive sets of highly focused improvisation. Music is an abstraction until it is heard. The derivation of music can stem from many sources, particular to the individual musician, particular to the way in w