Sonata postscript (4)
I believe the answer is:
coda
'sonata postscript' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for coda that I've seen before include "Final part of mus. structure" , "Word that modifies" , "End piece written for a piece of music" , "Tailpiece" , "noted conclusion" .)