Sinatra for one in French location (5)
I believe the answer is:
nancy
'french location' is the definition.
The definition suggests a singular noun which matches the answer.
'sinatra for one' is the wordplay.
I cannot quite understand how this works, but
'one' could be 'an' (an apple is one apple) and 'an' is present in the answer.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for nancy that I've seen before include "Birthplace of Edmond de Goncourt" , "Fruit" , "Dickensian heroine" , "Dickensian character who died" , "City in Lorraine" .)