Tamper with a note to get degree (9)
I believe the answer is:
doctorate
'degree' is the definition.
(doctorate is a kind of degree)
'tamper with a note' is the wordplay.
'tamper with' becomes 'doctor' (as in doctoring or manipulating an image).
'note' becomes 'te' (musical note).
'doctor'+'a'+'te'='DOCTORATE'
'to get' is the link.
(Other definitions for doctorate that I've seen before include "Highest academic degree" , "Highest degree in university" , "Academic qualification" , "Postgraduate degree" , "PhD or D.Phil" .)