Reportedly, country music was his forte (7)
I believe the answer is:
britten
'music was his forte' is the definition.
The definition suggests a singular noun which matches the answer.
'reportedly country' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'country' becomes 'Britain' (Britain is an example).
'britain' sounds like 'BRITTEN'.
Can you help me to learn more?
(Other definitions for britten that I've seen before include "Billy Budd composer" , "British composer associated with Aldeburgh" , "Composer of Peter Grimes" , "Composer born 1913" , "See 8" .)