Revise and rearrange a duet to include piano (6)
I believe the answer is:
update
'revise' is the definition.
(thesaurus)
'rearrange a duet to include piano' is the wordplay.
'rearrange' indicates anagramming the letters (I've seen this in other clues).
'to include' indicates putting letters inside.
'piano' becomes 'p'.
'a'+'duet'='aduet'
'aduet' with letters rearranged gives 'udate'.
'udate' going around 'p' is 'UPDATE'.
'and' acts as a link.
(Other definitions for update that I've seen before include "Supply latest info" , "account of the latest developments" , "Latest news" , "Modernise, modify" , "Brief" .)