Tries a change of style in humour (6)
I believe the answer is:
satire
'style in humour' is the definition.
'satire' can be an answer for 'humour' (satire is a kind of humour). I'm unsure of the 'style in' bit.
'tries a change' is the wordplay.
'change' indicates anagramming the letters.
'tries'+'a'='triesa'
'triesa' anagrammed gives 'SATIRE'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for satire that I've seen before include "Biting humour exposing vice, folly etc." , "Writings ridiculing vice and folly" , "Novel or play that ridicules social failings" , "Sarcastic humour" , "Mockery" .)