Among the latest YouTube finds, there is an upload of Trevor's official debut as a vocalist with the nascent version of Rabbitt in 1972. I say "official" because as long-time fans are aware he recorded the song "(Wake Up!) State Of Fear" with Freedom's Children (which included Ronnie Friedman on bass), but it was never released.
The first version of the cover of Jethro Tull's "Locomotive Breath" was, according to Trevor, originally suggested by someone at the record company as a single for release and recorded on a shoestring budget of $200. Producer Patric van Blerk had discovered his band the Conglomeration back in 1969 and so this particular production effort was seemingly part of his overall plan to get Trevor signed. As the Conglomeration had called it quits within the last year, this version of Rabbitt was a studio project featuring Ronnie's brother Errol on guitar, van Blerk's writing partner Fransua Roos on keyboards, and up-and-coming ZA musicians Lou Forer on bass and Cedric Samson on drums. The song's peak position on the Springbok Radio charts was number 18 in January 1973, the first of several entries for the band.
There were four singles credited to Rabbitt from 1972-1974, but the others appeared to be all original material, produced by either van Blerk or Robert John "Mutt" Lange. It's possible that the single "Yesterday's Papers" is the first to feature Trevor, Ronnie and Neil Cloud, as 1974 was the year they apparently reformed and were officially signed with Jo'Burg, according to Satbel A&R man Robin Taylor.
The first version of "Locomotive Breath" was subject to the typical censorship of the SABC, with a couple lines changed (the rerecorded version on Boys Will Be Boys! reverts to the correct lyrics) and adheres much closer to the arrangement of Jethro Tull's original, which recalls how many popular songs from overseas were rerecorded for the South African market at that time. Trevor performs in Ian Anderson's register, whereas in the 1975 version he's singing in his natural, higher range and the arrangement features a faster tempo. It's not surprising that Trevor would have desired to re-record the song for Rabbitt's debut album, with an arrangement and performance more in line with his own style and taste.