There was another one, from Liberty, entitled "Gutbucket - an Underworld Eruption". John Peel claimed that this referred to the complexions of some of the artists featured...

Good line up though - Captain Beefheart, Hapshash And The Coloured Coat, Lightnin' Hopkins, Alexis Korner, the groundhogs, the Nitty Gritty Dirt Band, Canned Heat, Ainsley Dunbar etc. And, beyond parody, the Bonzos with "Can Blue Men Sing The Whites".