Composition expected on time (4)
I believe the answer is:
duet
'composition' is the definition.
(I know that duet is a type of composition)
'expected on time' is the wordplay.
'expected' becomes 'due' (similar in meaning).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'time' becomes 't' (abbreviation).
'due'+'t'='DUET'
(Other definitions for duet that I've seen before include "Musical piece for two performers" , "Work for two players" , "Composition for two performers" , "Two singers performing together" , "Work for two performers" .)