A Finnish genre
of dance music
that was popular among elderly people
in 1960s. It drew its influence from Finnish and German dance music of 1920s and 1930s.
The name probably knomes from "oomp-pah" sound of tubas.
The "definitive" band of the genre is Humppa-Veikot; These days, the more well known band is Eläkeläiset, though Eläkeläiset makes just parodies of songs and not "serious" humppa (this may be reason why they're, uh, popular among younger generation. =)
Nuggets of information paraphrased from... um, music encyclopedia. I forgot the title and ISBN, got to find 'em later... more information wouldn't hurt either...
Also, a humppa tune from Eläkeläiset, to the tune of Zombie by The Cranberries. (I'll put the lyrics here as soon as I find them and make a rough translation =)