T. Rex, originally Tyrannosaurus Rex, were an English rock band formed in London in 1967 by singer-songwriter and guitarist Marc Bolan, who was their leader, frontman and only consistent member. Originally an acoustic psychedelic folk band, Bolan began to change the band's style towards electric rock with their fourth album, 1970's A Beard of Stars, and shortened their name to T. Rex by the time their self-titled fifth album was released later that same year. This development culminated with their first significant hit single "Ride a White Swan", and the group soon became pioneers of the glam rock movement.