Mover to music (6)
I believe the answer is:
dancer
'mover to music' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for dancer that I've seen before include "Mover to music" , "One of Santa's reindeer" , "Ballerina cared desperately about Nureyev's lead" , "One moves to music" , "behind Rudolph" .)