Band with heart of gold in Asian city (7)
I believe the answer is:
colombo
'asian city' is the definition.
(I've seen this before)
'band with heart of gold' is the wordplay.
'band' becomes 'combo' (combo can mean a musical group).
'with' means one lot of letters goes inside another.
'heart of' means to look at the middle letters.
The middle letters of 'gold' are 'ol'.
'combo' enclosing 'ol' is 'COLOMBO'.
'in' acts as a link.
(Other definitions for colombo that I've seen before include "Sri Lankan port" , "Main port of Sri Lanka" , "City of Sri Lanka" , "Capital of Sri Lanka" , "Sri Lankan capital" .)