John Anthony David Sloman was born in Cardiff (South Wales), 26 April 1957 as the eldest of six children. He is a former member of Trapper, Pulsar, Lone Star, and Uriah Heep (between 1979–1981). While in Uriah Heep, Sloman took over lead vocal duties from J. Lawton. Additionally, Sloman played Keyboards.
After Uriah Heep, he formed the band 'John Sloman's Badlands' and showcased several songs at The Marquee Theatre. 'John Sloman's Badlands' featured former Trapper drummer John Munro and Whitesnake's John Sykes and Neil Murray. The band were ultimately passed over and John went on to record the first of his solo albums Disappearances Can Be Deceptive produced in part by Todd Rundgren. John Sykes from the UK Badlands and Ray Gillen from the U.S. band with the same name played together in Blue Murder (though Gillen left during the recording of the first album and Sykes then re-recorded all the vocals by himself). Badlands broke up upon Sykes joining the band Thin Lizzy. Sykes and Murray later played together in Whitesnake on the U.S. version of Slide It In and on the Whitesnakealbum.