Drunk Merlot that's initially oaky with a wavering type of note (7)
I believe the answer is:
tremolo
'a wavering type of note' is the definition.
'drunk merlot that's initially oaky' is the wordplay.
'drunk' indicates an anagram.
'that's initially' suggests taking the first letters.
The first letter of 'oaky' is 'o'.
'merlot' is an anagram of 'tremol'.
'tremol'+'o'='TREMOLO'
'with' is the link.
(Other definitions for tremolo that I've seen before include "Violin's rapid repetition of a single note" , "Fluctuation in pitch" , "Vibrating musical effect" , "Paganini's effect" , "Wavering note" .)