Nisennenmondai, beside being a nearly unimaginably difficult to say name, is a Japanese noise trio. Their music is fully instrumental and they seem to favor long, building tracks. Almost sound like what a band like Battles might be if they took out vocals and loud guitar playing. Now, I know that can sound unappealing, but I assure you it is really mesmerizing and rather joyful sounding.
To be had here:
Nisennenmondai - Destination Tokyo [224 VBR kbps]