"Goodnight" girl of song (5)
I believe the answer is:
irene
'goodnight girl of song' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for irene that I've seen before include "- - Handl, actress" , "Girl's name (meaning Peace)" , "Greek goddess of peace (English name)" , "Peaceful girl" , "Greek godess of peace" .)