Devil concealing tail goes around performing musical form (6)
I believe the answer is:
sonata
'musical form' is the definition.
(I've seen this in another clue)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for sonata that I've seen before include "eg Moonlight, Kreutzer" , "See 6" , "musical performance" , "Moonlight, perhaps" , "Instrumental work" .)