Good sort of piano (7)
I believe the answer is:
upright
I believe this clue is a double definition.
'good' is the first definition.
('upright' can be a synonym of 'good')
'sort of piano' is the second definition.
(I've seen this before)
(Other definitions for upright that I've seen before include "Erect - honest" , "Vertical like rugby goal post" , "Honourable; erect" , "Key item" , "Keyboard instrument" .)