Made a piano in the shed (6)
I believe the answer is:
shaped
'made' is the definition.
(shaping is a kind of making)
'a piano in the shed' is the wordplay.
'piano' becomes 'p'.
'in' is an insertion indicator.
'a'+'p'='ap'
'ap' placed into 'shed' is 'SHAPED'.
(Other definitions for shaped that I've seen before include "Given a certain form - phased accordingly" , "Sculpted" , "Formed or fashioned" , "Formed - moulded" , "Gave form to" .)