In concert, playing duet with flipping hot content (6)
I believe the answer is:
united
'in concert' is the definition.
(thesaurus)
'playing duet with flipping hot content' is the wordplay.
'playing' is an anagram indicator.
'with' is an insertion indicator.
'flipping' is a reversal indicator.
'hot content' becomes 'in' (I can't justify this - if you can you should give a lot more credence to this answer).
'in' backwards is 'ni'.
'duet' with letters rearranged gives 'uted'.
'uted' enclosing 'ni' is 'UNITED'.
Can you help me to learn more?
(Other definitions for united that I've seen before include "See 1" , "Joined into a single entity" , "Joined together, allied" , "... we stand, divided we fall" , "joined with others" .)