Music: Dem Bones

A spaced-out premiere

The scene at St. Mary's Cathedral in San Francisco was vaguely surreal. In the pews was an audience of 1,500, sedate as any churchgoers. Ranged about them in a huge semicircle was a gleaming array of 80 trombonists, as if a parade had lost its way and sought sanctuary.

But when the music began, the sound was a far cry from Sousa. Separated by staccato commentaries from the cathedral's pipe organ, densely dissonant sonorities clashed and blended over the listeners' heads. Full-throated blares, splintery muted phrases, the crooning tones of the soprano trombone, the rumble of its contrabass relative—all...