Almost swell out with song in the country (8)
I believe the answer is:
bulgaria
'the country' is the definition.
(Bulgaria is an example)
'almost swell out with song' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'swell out' becomes 'bulge' (I've seen this before).
'with' is a charade indicator (letters next to each other).
'song' becomes 'aria' (piece of music in an opera).
'bulge' with its final letter taken off is 'bulg'.
'bulg'+'aria'='BULGARIA'
'in' is the link.
(Other definitions for bulgaria that I've seen before include "I bar Gaul from the country" , "Its capital is Sofia" , "Romania's southern neighbour" , "Balkan republic" , "in E" .)