A South American city so songlike (6)
I believe the answer is:
arioso
'songlike' is the definition.
(I've seen this in another clue)
'a south american city so' is the wordplay.
'south american city' becomes 'rio' (Rio de Janeiro in Brazil).
'a'+'rio'+'so'='ARIOSO'
(Other definitions for arioso that I've seen before include "Lyrical piece" , "piece of music is discovered" , "Song-like (Italian)" .)