A Schubert piece with heart (3)
I believe the answer is:
hub
'heart' is the definition.
(hub is a kind of heart)
'a schubert piece with' is the wordplay.
'with' indicates a hidden word.
'HUB' is hidden in the letters of 'schubert piece'.
(Other definitions for hub that I've seen before include "Centre (of network)" , "Nave of a wheel" , "Centre of wheel" , "Focal point of activity" , "Central part of a car wheel" .)