Here are some suggestions for collective nouns for singers and musicians, a la Animal Collectives.
screech of sopranos
moan of altos
howl of tenors
rumble of basses
wisp of flutes
groan of clarinets
moan of oboes
scream of trumpets
fanfare of trumpets
flourish of trumpets
blast of trombones
smear of trombones
croak of tubas
pound of drums
crash of cymbals
tramp of timpani
screech of violins
scratch of violas