Musical speed (5)
I believe the answer is:
tempo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">musical speed</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for tempo that I've seen before include "Rate and rhythm in music" , "Pace of a musical piece" , "Metronome output" , "Speed or beat, musically" , "Speed at which piece of music is played" .)