Suffice it to say, Songsmith is one of those cool research projects at Microsoft -- you sing a song into the microphone and tell it a musical style, then Songsmith analyses the tune, rhythm and so forth to create backing tracks. Which sounds innocent enough, but it has apparently spawned a little industry of taking real pop videos, stripping them down to just the vocals, feeding them through Songsmith and then reattaching the tune to the original video.
The results are -- well, just read the article and check out the attached videos. Surely, the world didn't *need* a chirpy bluegrass version of Billy Idol singing "White Wedding", but it's scary-funny...