The tenors have the melody, which is "Auld Lang Syne," but it took me till the other day to realize that was what it was, since I've been singing treble or alto and the melody does not dominate the arrangement in any case.

The one that blew my mind, I know as "The Men of the West/Rosin the Beau." Only in a different time signature, and slightly less revolutionary and/or drunk.