Piece of music in the pub? (3)
I believe the answer is:
bar
This clue is a double definition.
'piece of music' is the first definition.
(bar of music)
'pub?' is the second definition.
(both are drinking establishments)
'in the' is the link.
(Other definitions for bar that I've seen before include "Lawyers collectively" , "Lawyers may be called to it" , "Ingot" , "See 9" , "In Mississippi, measure" .)