Wrong note is better (5)
I believe the answer is:
outdo
'is better' is the definition.
(thesaurus)
'wrong note' is the wordplay.
'wrong' becomes 'out' (eg a calculation might be 'out'**).
'note' becomes 'do'.
'out'+'do'='OUTDO'
(Other definitions for outdo that I've seen before include "going to top?" , "Be better in performance (than another person)" , "Surpass someone at something" , "Overcome" , "Surpass, go one better than" .)