Musical shake? Lot more wobbly! (7)
I believe the answer is:
tremolo
'musical shake?' is the definition.
(I've seen this before)
'lot more wobbly' is the wordplay.
'wobbly' indicates an anagram.
'lot'+'more'='lotmore'
'lotmore' is an anagram of 'TREMOLO'.
(Other definitions for tremolo that I've seen before include "Violin's rapid repetition of a single note" , "Musical shake" , "Vocal vibrato -- lot more (anag)" , "Wavering note" , "A vibrating effect in music" .)