About the piano duet, is creating strife (7)
I believe the answer is:
dispute
'strife' is the definition.
(thesaurus)
'about the piano duet is' is the wordplay.
'about' indicates an anagram.
'the piano' becomes 'p' (musical abbreviation).
'p'+'duet'+'is'='pduetis'
'pduetis' anagrammed gives 'DISPUTE'.
'creating' acts as a link.
(Other definitions for dispute that I've seen before include "Argument, contention" , "Disagree or challenge" , "Altercation" , "Altercate" , "Row" .)