On this day in 1973 a heavy metal and prog rock album announced the arrival of one of the greatest bands in rock history with their eponymous debut.

Queen had been gigging since 1970 and a lucky break had offered them the chance to road test brand-new recording facilities at De Lane Lea Studios in Dean Street, Soho. The resulting slick five-track demo included eventual debut single Keep Yourself Alive but only attracted one, unacceptable and low, record deal offer.

Luckily, producers John…