Spectrum was formed in Melbourne in 1969 by Mike Rudd, a New Zealand-born singer, songwriter and guitarist (ex-Chants R&B, The Party Machine, Sons of the Vegetal Mother), together with bassist Bill Putt (Gallery, The Lost Souls), organist Lee Neale (ex-Nineteen 87), and drummer Mark Kennedy. Spectrum played covers of Traffic, Soft Machine and Pink Floyd initially, they then developed their own style and wrote a set of original material. Just prior to being signed up by EMI, Spectrum cut a demo single which they hawked to record companies as a 7" acetate. One side was an early, folky version of "I'll Be Gone", according to rock historian Ian McFarlane, these acetates are now "impossibly rare" and only two or three copies are known to have survived.