Ronald has to perform this piece (5)
I believe the answer is:
rondo
'this piece' is the definition.
(type of musical composition)
'ronald has to perform' is the wordplay.
'ronald' becomes 'ron' (I've seen this in other clues).
'has' is a charade indicator (letters next to each other).
'to perform' becomes 'do' (both can mean complete an action).
'ron'+'do'='RONDO'
(Other definitions for rondo that I've seen before include "Piece of music with recurring theme" , "Music with repeated refrains" , "Musical piece with a recurring theme" , "has repetitive theme" , "Type of movement" .)