Bad jokes about quiet European capital (6)
I believe the answer is:
skopje
'european capital' is the definition.
(capital of North Macedonia)
'bad jokes about quiet' is the wordplay.
'bad' indicates an anagram.
'about' means one lot of letters goes inside another.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'jokes' with letters rearranged gives 'skoje'.
'skoje' enclosing 'p' is 'SKOPJE'.
(Other definitions for skopje that I've seen before include "capital city" , "somewhere in Balkans" , "Capital of FYR Macedonia" , "place in Balkans" , "foreign capital" .)