A Sinatra in French city (5)
I believe the answer is:
nancy
'french city' is the definition.
(city in France)
'a sinatra' is the wordplay.
I cannot really understand how this works, but
'a' could be 'an' and 'an' is found in the answer.
This explanation may well be incorrect...
'in' is the link.
Can you help me to learn more?
(Other definitions for nancy that I've seen before include "City in Lorraine" , "Girl's name; NE French city" , "Dickensian heroine" , "Girl; French city" , "Dickensian character who died" .)