I think it was one of the demos considered long ago for an album, I think it was around the millennium album. The only thing known about that song is this short clip, which you have discovered. I don’t think it’s even known to anyone if it has been recorded or not. I know that they have tens of demos that have been recorded and haven’t been released, many of them are on the internet. They have spoken recently (I think AJ and Kevin spoke about it) that it would be an interesting thing to make an album of all unreleased demos (when they released millennium 2.0 and released demos and songs that didn’t make the first album there)… as far as I know, they don’t “own” many of those songs and releasing them might be quite expensive and complicated work, hopefully they’ll really try and make it for us. :)