Performer of an early version on the piano (6)
I believe the answer is:
player
'performer' is the definition.
(I know that player is a type of performer)
'an early version on the piano' is the wordplay.
'version' is an anagram indicator.
'on' is a charade indicator (letters next to each other).
'the piano' becomes 'p' (musical abbreviation).
'early' anagrammed gives 'layer'.
'layer' after 'p' is 'PLAYER'.
'of' acts as a link.
(Other definitions for player that I've seen before include "Professional musician - team sportsperson" , "Contestant" , "Actor - footballer?" , "Competitor; musician" , "Sports participant" .)