Essentially, Jeffreys worked with the same core of musicians on "Truth Serum" as on "The King of In Between", including Steve Jordan (Eric Clapton)  and Larry Campbell ( Tom Petty ) , as well as Zev Katz, Duke Levine and Brian Mitchell. The declared goal was to capture the immediacy, the intimacy and the euphoric energy of the demo recordings in the studio as well. So the band gathered around the cassette deck in Andy Taub's Brooklyn Recordings studio and internalized the songs purely by ear, which were then mostly recorded in one go, in a live take with unpolished vocals. There was a very relaxed atmosphere at these sessions; the door was open to everyone, with the result that some friends popped in for unexpected guest performances. Noted songwriter James Maddock even joined Campbell as co-producer, and singer Cindy Mizelle made an appearance on the ska-reggae number "Dragons To Slay," as did Art Baron, the last saxophonist under Duke Ellington's aegis . Andy Taub even left the mixing desk in the middle of a recording to spontaneously join the band at the glockenspiel.