1) European folk dance 
Boombal (pl. Boombals) is the name given to a relatively recent phenomenon of folk dance parties in Belgium, originating in the French bal folk. The partygoers indulge in pair, ring, line, and string dances such as the waltz, polka, An Dro, etc. adapted from the French bal folk scene. The events are seen as a more social and enjoyable alternative ...