Tore off from opera, back at top speed to dance (6)
I believe the answer is:
cavort
'dance' is the definition.
(thesaurus)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for cavort that I've seen before include "Frolic, gambol" , "Gambol, play about" , "Caper about excitedly" , "Dance with glee" , "Skip" .)