Lemmy

... was never really the frontman of Hawkwind, although he did sing lead vocals on their biggest hit, Silver Machine. He joined Hawkwind as bass guitarist in 1971, following the release of their second album, and was sacked four years later because of his "erratic behaviour". He then, to quote Wikipedia, "founded Motörhead during the same year as the lead singer, bassist, songwriter and frontman."

Hawkwind have never really had a frontman. Their only constant member is Dave Brock – founder, singer, songwriter and guitarist. But – to quote Wikipedia again – "on stage, his preference is to remain at the back and let others take centre stage and be the focus of attention, to the point where he will often employ dancers, mime artists and fire eaters to fill that space. At other times (particularly in their early days), the entire band is totally obscured by their light show."