Notes intend to discredit (6)
I believe the answer is:
demean
'discredit' is the definition.
(I've seen this before)
'notes intend' is the wordplay.
'notes' becomes 'de' (two musical notes).
'intend' becomes 'mean' (meaning is a kind of intending).
'de'+'mean'='DEMEAN'
'to' acts as a link.
(Other definitions for demean that I've seen before include "Lower in dignity or reputation" , "Debase" , "Lower, degrade" , "'Put down, degrade (6)'" , "make base" .)