Maestro's opera not at first accepted by the writer (9)
I believe the answer is:
toscanini
'maestro's' is the definition.
(I've seen this before)
'opera not at first accepted by the writer' is the wordplay.
'opera' becomes 'tosca' (Giacomo Puccini opera).
'at first' suggests taking the first letters.
'accepted by' becomes 'in' (I've seen this in other clues. I am not sure about the 'by' bit.).
'the writer' becomes 'I' (the person who is writing these clues).
The initial letter of 'not' is 'n'.
'tosca'+'n'+'in'+'i'='TOSCANINI'
Can you help me to learn more?
(Other definitions for toscanini that I've seen before include "Virtuoso conductor" , "Bare rock formation" , "Arturo --, Italian conductor" , "He conducted" , "Maestro" .)