After overture to opera I put in part for songster (6)
I believe the answer is:
oriole
'for songster' is the definition.
(thesaurus)
'after overture to opera i put in part' is the wordplay.
'after' means one lot of letters go next to another.
'overture to' says to take the initial letters (overture can mean the beginning of something).
'put in' is an insertion indicator.
'part' becomes 'role' (eg a theatrical role).
The initial letter of 'opera' is 'o'.
'i' inserted within 'role' is 'riole'.
'o' next to 'riole' is 'ORIOLE'.
(Other definitions for oriole that I've seen before include "Golden-yellow bird" , "Bird, Baltimore --" , "Did Leo or I hear the tropical songbird?" , "Black and yellow US bird" , "Bird of which male has black and yellow plumage" .)