It's totally agreed that you'll never know what to expect with Frank Zappa, be it with the Mothers of Invention or his solo stuff. Over-Nite Sensation was basically the third version of the Mothers, which by this time pretty much exists in name only. The only connection you have with the original Mothers of Invention from the 1960s, other than Zappa himself was Ian Underwood, and he didn't join the band until 1967. Ralph Humphries, Ruth Underwood, Ricky Lancelotti, Jean-Luc Ponty, Tom Fowler, and George Duke are some of the other members helping out. Tina Turner, uncredited, even provided some backing vocals, especially on "Zomby Woof". Jean-Luc Ponty is obviously a well-known figure in jazz and fusion circles, having played with the likes of Elton John, Zappa's earlier album Hot Rats (1969), as well as a string of album under his own name, including one called King Kong (named after a composition from Uncle Meat, of course) which was obviously a collection of Zappa songs done by Ponty. Tom Fowler was one a member of the San Francisco band It's a Beautiful Day, he wasn't on their 1969 debut that had the hit "White Bird", but their 1971 album Choice Quality Stuff/Anytime (their third album).