In December 1968, to fulfill contractual obligations, Soft Machine re-formed with former road manager and composer Hugh Hopper on bass added to Wyatt and Ratledge and recorded their second album, "Volume Two" (1969), which started a transition toward jazz fusion. In May 1969 this line-up acted as the uncredited backing band on two tracks of "The Madcap Laughs", the debut album by Syd Barrett. In 1969 the trio was expanded to a septet with the addition of four horn players, though only saxophonist Elton Dean remained beyond a few months, the resulting Soft Machine quartet (Wyatt, Hopper, Ratledge and Dean) running through "Third" (1970) and "Fourth" (1971), with various guests, mostly jazz players (Lyn Dobson, Nick Evans, Mark Charig, Jimmy Hastings, Roy Babbington, Rab Spall). "Fourth" was the first of their fully instrumental albums and the last one featuring Wyatt.