Vibrato (7)
I believe the answer is:
tremolo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">vibrato</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that tremolo is a type of vibrato)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tremolo that I've seen before include "Vibrato effect" , "Wavering note" , "Violin's rapid repetition of a single note" , "Musical wavering effect" , "Shaky effect in music" .)