Composed sounds (5)
I believe the answer is:
music
'composed sounds' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for music that I've seen before include "Country, say" , "(Pleasant) sequence of sounds" , "Strains" , "'''If ... be the food of love, play on'' (Twelfth Night) (5)'" , "Aural art" .)