Faust for one bewildered by sound of capital city (4,4)

I believe the answer is:
lost soul
'sound of capital city' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'faust for one bewildered' is the wordplay.
'faust' becomes 'soul' (I can't justify this - if you can you should believe this answer much more).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'one bewildered' becomes 'lost' (I've seen this in another clue).
'soul' put after 'lost' is 'LOST SOUL'.
'by' is the link.
Can you help me to learn more?
(Other definitions for lost soul that I've seen before include "One unable to cope with everyday life" , "Damned" , "Irredeemably evil person" , "Hopelessly evil person" , "reprobate" .)
