French city, but the name is changed (6)
I believe the answer is:
amiens
'french city' is the definition.
(I've seen this before)
'the name is changed' is the wordplay.
'changed' is an anagram indicator.
'name'+'is'='nameis'
'nameis' is an anagram of 'AMIENS'.
'but' is the link.
(Other definitions for amiens that I've seen before include "French cathedral city on the river Somme" , "European town" , "capital of Picardy" , "City of NE France" , "City in northern France" .)