On first sight, I guess it appeared full of potential. But on further reflection, and listening, what you have is two very single-minded people — albeit of the same school — who had fearsome reputations for bending their groups to their iron (and eccentric) wills. But can they splice their DNA and forge a real collaboration? No. Sam with the Showing Scalp Flat Top and Man with the Woman Head are just Beefheart songs — how could they be anything else with titles like those? — and the Captain does his thing while Zappa's band of Mothers noodle abstractly in the background. Most of the other songs sound like Zappa pieces with a guest vocalist.
Many years ago — I can't remember whether it was at school or university — I heard the story about Zappa and Beefheart having a "gross out" competition on stage. One started things off by taking a crap on the stage; the other upped the ante by eating it. Years later I read The Real Frank Zappa Book in which Frank himself recounts the story at the beginning of Chapter 1, telling how many people have come up and told him how "cool" they thought it was, and the he goes on to assert that nothing of the kind ever happened. It's like the old one about the rock star who had his stomach pumped and they found a pint (or a gallon!) of semen. You can tell someone's age by the name of the rock star involved. If you went to school in the '70s, it was Elton John, David Bowie or (in my case) Rod Stewart. School playgrounds in the '80s changed it to Marc Almond or Jon Bon Jovi; in the '90s Alanis Morrissette.
MusicBrainz entry for this album
Wikipedia entry for this album
Rate Your Music entry for this album
Listen to none of this album at Last.fm