Heard songbird in French city (6)
I believe the answer is:
rennes
'french city' is the definition.
(I've seen this before)
'heard songbird' is the wordplay.
'heard' shows a homophone (sound like).
'songbird' becomes 'wren' (type of songbird).
'wren' is a homophone of 'RENNES'.
'in' is the link.
(Other definitions for rennes that I've seen before include "Major town in Brittany" , "City of Brittany" , "French city" , "Hurries" , "City of NW France" .)