French writer's visiting pianist occasionally in city (9)
I believe the answer is:
inverness
'city' is the definition.
(I have seen 'Scottish city ' mean 'inverness' so perhaps 'city' could also mean 'inverness')
'french writer's visiting pianist occasionally' is the wordplay.
'french writer's' becomes 'verne's' (author Jules Verne).
'visiting' indicates putting letters inside.
'occasionally' indicates alternate letters (letters taken at regular intervals or occasions).
The alternate letters of 'pianist' are 'ins'.
'vernes' put within 'ins' is 'INVERNESS'.
'in' acts as a link.
(Other definitions for inverness that I've seen before include "Highland city" , "overcoat" , "Scottish Highlands city" , "northern city" , "Scottish highland town" .)