Determined to return notes (3,2)
I believe the answer is:
set on
'determined' is the definition.
(I've seen this before)
'return notes' is the wordplay.
'return' shows that the letters should be reversed in order.
'notes' in reverse letter order is 'SET ON'.
'to' is the link.
(Other definitions for set on that I've seen before include "Go" , "Determined" , "Attack" .)