Leading recitalist performing party piece (5)
I believe the answer is:
rondo
'piece' is the definition.
(type of musical composition)
'leading recitalist performing party' is the wordplay.
'leading' indicates taking the first letters (the leading letter of the word).
'performing' becomes 'on' (as in being on stage).
'party' becomes 'do' (do can informally mean a party).
The first letter of 'recitalist' is 'r'.
'r'+'on'+'do'='RONDO'
(Other definitions for rondo that I've seen before include "Musical work" , "Music form with repeating theme" , "A collection of notes" , "has repetitive theme" , "rota, maybe" .)