It is a golden wedding party somewhere in Scandinavia and the guests are getting together to sing their own version (presumably with words relevant to the couple) of Verdi's March of the Hebew Slaves from Aida. They are all totally legless and it is very funny - or it made me laugh anyway.
www.youtube.com/watch?v=1zeX4doJypo
Book Title by Their Authors (Parlour Game)

