Bard's instrument (4)
'bard's instrument' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lute that I've seen before include "Ancient stringed instrument" , "Elizabethan stringed instrument" , "Old stringed instrument with a pear-shaped body" , "Play instrument" , "Old plucked instrument" .)
(Other definitions for lyre that I've seen before include "Ancient Greek stringed instrument" , "Ancient Greece harp" , "Rely (anag.)" , "used to produce music" , "Ancient harp-like instrument" .)