The notes you keep from (7)

I believe the answer is:
refrain
'keep from' is the definition.
(thesaurus)
'the notes you' is the wordplay.
I cannot quite understand how this works, but
'notes' could be 'ef' and 'ef' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for refrain that I've seen before include "Don't do that - it's a song" , "Chorus; desist" , "Forbear from chorus?" , "Chorus; keep away (from)" , "Chorus of a song" .)
