Famous as a piece of music? (5)
I believe the answer is:
noted
I believe this clue is a double definition.
'famous' is the first definition.
(noted can mean well-known or famous)
'as a piece of music?' is the second definition.
(a piece of music has musical notes)
(Other definitions for noted that I've seen before include "Renowned" , "Toned (anag.)" , "Made a record - celebrated" , "Remarkable" , "Wrote it down" .)