Show the lady is playing the piano in (7)
I believe the answer is:
display
'show' is the definition.
(display is a kind of show)
'the lady is playing the piano in' is the wordplay.
'playing' indicates anagramming the letters.
'the piano' becomes 'p'.
'in' is an insertion indicator.
'lady'+'is'='ladyis'
'ladyis' anagrammed gives 'dislay'.
'dislay' going around 'p' is 'DISPLAY'.
(Other definitions for display that I've seen before include "Showcase" , "Show or arrange" , "Place on show" , "Show to the public" , "Exhibition" .)