Perhaps compound time in musical (7)
I believe the answer is:
reagent
'perhaps compound' is the definition.
'reagent' can be an answer for 'compound' (thesaurus). I am not certain of the 'perhaps' bit.
'time in musical' is the wordplay.
'time' becomes 'age' (an age is a period of time).
'in' means one lot of letters goes inside another.
'musical' becomes 'rent' (Rent is an example).
'age' going within 'rent' is 'REAGENT'.
Can you help me to learn more?
(Other definitions for reagent that I've seen before include "Reacting substance" , "Substance with characteristic reactions, used as a chemical test" , "Chemical with known properties" , "Active chemical" , "Chemically active substance" .)