Pub customer initially alone, sadly, in city (9)
I believe the answer is:
barcelona
'in city' is the definition.
(I've seen this before)
'pub customer initially alone sadly' is the wordplay.
'pub' becomes 'bar' (I've seen this before).
'initially' indicates taking the first letters.
'sadly' indicates anagramming the letters.
The initial letter of 'customer' is 'c'.
'alone' is an anagram of 'elona'.
'bar'+'c'+'elona'='BARCELONA'
(Other definitions for barcelona that I've seen before include "City and province of Catalonia in NE Spain" , "Largest Spanish port" , "Span. City" , "coastal city" , "9/11 [OLYMPIC VENUE]" .)