oh, pendex, "polka music" doesn't translate as "polka musica". that sounds petarded in spanish. we'd simply call it "polka" cuz we know it's music (polka is a noun). if we put add an adjective, we add it after the noun. e.g. musica clįsica.
more videos for you:
http://www.youtube.com/watch?v=Bc0Vv3cNsFA