Pace of a piece of music (5)
I believe the answer is:
tempo
'pace of a piece of music' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for tempo that I've seen before include "Speed or beat, musically" , "Speed of a musical piece" , "Speed at which a musical composition is to be played" , "Rate and rhythm in music" , "Rhythm or speed as in music" .)