One of The Commotions turns up for Bud and loud music (4)
I believe the answer is:
flap
'one of the commotions' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'turns up for bud and loud music' is the wordplay.
'turns up' says the letters should be written in reverse.
'for bud' becomes 'pal' (I can't justify this - if you can you should believe this answer much more).
'and' means one lot of letters go next to another.
'loud music' becomes 'f' (forte - musical term meaning loud).
'pal' back-to-front is 'lap'.
'lap' put after 'f' is 'FLAP'.
Can you help me to learn more?
(Other definitions for flap that I've seen before include "Moving surface on wing" , "Be agitated; hinged piece" , "Use wings; be agitated" , "Agitated state; tab" , "Excitement" .)