Copy a note for a girl (5)
I believe the answer is:
mimic
'copy' is the definition.
(mimicking is a kind of copying)
'a note for a girl' is the wordplay.
'a note' becomes 'c' (musical note).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'a girl' becomes 'mimi' (**).
'c' after 'mimi' is 'MIMIC'.
(Other definitions for mimic that I've seen before include "Impersonator" , "Copy (voice, mannerisms)" , "Go round a bend (in car)" , "Impressionist" , "Appear just like" .)