Composition for performance by a band? (8)
I believe the answer is:
concerto
'composition' is the definition.
(I have seen 'Musical composition' mean 'concerto' so perhaps 'composition' could also mean 'concerto')
'performance by a band?' is the wordplay.
'performance' becomes 'concert' (concert is a kind of performance**).
'by' means one lot of letters go next to another.
'a band?' becomes 'o' (I've seen this in other clues).
'concert'+'o'='CONCERTO'
'for' is the link.
(Other definitions for concerto that I've seen before include "Piece for soloist and orchestra" , "piece of music" , "Orchestral work for solo instrument" , "Work for soloist and orchestra" , "10 [COMPOSITION]" .)