Piano phrase rewritten maybe (7)
I believe the answer is:
perhaps
'maybe' is the definition.
(synonyms)
'piano phrase rewritten' is the wordplay.
'piano' becomes 'p'.
'rewritten' is an anagram indicator.
'phrase' anagrammed gives 'erhaps'.
'p'+'erhaps'='PERHAPS'
(Other definitions for perhaps that I've seen before include "say" , "Could be, maybe" , "Possibly but not certainly" , "It may be" , "Not necessarily" .)