Musical portion's over, captured by microphone (7)
I believe the answer is:
melodic
'musical' is the definition.
(thesaurus)
'portion's over captured by microphone' is the wordplay.
'portion' becomes 'dole' (dole is a kind of portion**).
'over' shows that the letters should be reversed in order.
'captured by' means one lot of letters goes inside another.
'microphone' becomes 'mic'.
'dole' backwards is 'elod'.
'elod' inserted into 'mic' is 'MELODIC'.
(Other definitions for melodic that I've seen before include "Pleasantly musical" , "Pleasant-sounding" , "nice on the ear" , "Old mice (anag.)" , "Harmonious" .)