Romantic musical composition is hit performance for the audience (8)
I believe the answer is:
nocturne
'romantic musical composition' is the definition.
'nocturne' can be an answer for 'composition' (nocturne is a kind of musical composition). I'm unsure of the 'romantic musical' bit.
'hit performance for the audience' is the wordplay.
I cannot really understand how this works, but
'performance' could be 'turn' (turn is a kind of performance) and 'turn' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'is' is the link.
Can you help me to learn more?
(Other definitions for nocturne that I've seen before include "Picture of a night scene" , "Dark scene" , "Chopin piece" , "Piece of dreamy music" , "Dreamy instrument music" .)