That's part of the early Brownies show they did on January 6th, 2000 - almost 9 years ago, damn! They played two other Unknown Songs, and others like sagganuts, a minor 4-4, and a bunch of others. Really different style of music, and lyrics as well.

You can also watch the Arlene's Grocery show (April 2000) here: http://uk.youtube.com/watch?v=UoTaxh_rt0Y (check the description for more information)