Not as a version for piano, perhaps (6)
I believe the answer is:
sonata
'piano perhaps' is the definition.
I can't tell whether this defines the answer.
'not as a version' is the wordplay.
'version' indicates an anagram.
'not'+'as'+'a'='notasa'
'notasa' anagrammed gives 'SONATA'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for sonata that I've seen before include "Solo piano composition" , "Musical composition with three or more contrasting movements" , "See 6" , "piece for instrumental soloist" , "Musical composition for a solo instrument" .)