Some writer on Donizetti identifying piece with recurrent theme (5)
I believe the answer is:
rondo
'piece with recurrent theme' is the definition.
'rondo' can be an answer for 'piece' (type of musical composition). I am not sure about the 'with recurrent theme' bit.
'some writer on donizetti' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'RONDO' is hidden in the letters of 'writer on donizetti'.
'identifying' is the link.
Can you help me to learn more?
(Other definitions for rondo that I've seen before include "Piece of music with repeated refrain" , "rota, maybe" , "Musical form with recurring theme" , "Donor (anag) - piece of music" , "Musical form with repeated theme" .)