Silence in composition on the radio (5)
I believe the answer is:
peace
'silence' is the definition.
(I've seen this in another clue)
'composition on the radio' is the wordplay.
'composition' becomes 'piece' (synonyms).
'on the radio' indicates a 'sounds like' (homophone) clue.
'piece' is a homophone of 'PEACE'.
'in' is the link.
(Other definitions for peace that I've seen before include "'Calm, harmony (5)'" , "Caught" , "Quiet companion" , "Absence of conflict" , "Calmness" .)