Perform piano backing with troupe's online show (7)
I believe the answer is:
podcast
'online show' is the definition.
(I've seen this in another clue)
'perform piano backing with troupe's' is the wordplay.
'perform' becomes 'do' (both can mean complete an action).
'piano' becomes 'p' (musical abbreviation).
'backing' shows that the letters should be reversed in order.
'with' says to put letters next to each other.
'troupe' becomes 'cast' (I've seen this before).
'do'+'p'='dop'
'dop' back-to-front is 'pod'.
'pod'+'cast'='PODCAST'
(Other definitions for podcast that I've seen before include "Downloadable programme" , "Download" , "Audio file distributed over the internet" , "Web feed" , "internet feature" .)