Note rubbish sparkle (7)
I believe the answer is:
glitter
'sparkle' is the definition.
(I know that sparkle can be written as glitter)
'note rubbish' is the wordplay.
'note' becomes 'g' (musical note).
'rubbish' becomes 'litter' (litter is a kind of rubbish).
'g'+'litter'='GLITTER'
(Other definitions for glitter that I've seen before include "Are bright" , "Glisten, sparkle" , "Sparkling decoration" , "Flashiness" , "addition to Christmas card" .)