Ievan Polkka has words. Its a Finnish polka song written in the 1930s, its modern popularity is due to its appearance in an anime, no idea which. Not made up lyrics, just in a foreign language.
Edit: Actually I'm wrong. Its similar to "scat" songs in that it has very few actual words. So, yes, no lyrics in the modern version of that song. Carry on.
They are sung in “Panzerese”, a language spoken within the world of the series, created to provide a unique feeling and identity. Thanks to this, there is an unparalleled sensation to the music created by Saori Kobayashi, unmatched by any other vocal theme on any other SEGA game.
Damn near every Rap song from 2004 (Crunk Era) to 2008 (???)
LOL hocus pocus i actually like that one though. I think there is a Boondocks rap with only syllables and (not any real words), i'd have to dig for it in youtube.