The Song:In order for it to feel more authentic, Beck filled out his
Song Reader book with fragments of songs and melodies, as well as fictional album collections and made-up album titles. "The Little Mustache That Belongs" is listed as part of the album,
Songs Of The Hill Country - Sacred And Native American Melodies.
Many, if not most, of the song titles on the back of "Saint Dude" are references to older sheet music/songs, though some are jokes. I have to figure this is some sort of reference to a joke, but I was unable to figure it out exactly.