Pentagram is an American heavy metal band from Alexandria, Virginia, most famous as one of the pioneers of heavy metal, and the subgenre of doom metal in particular. As such, they are considered as one of the "big four of doom metal", alongside Candlemass, Saint Vitus and Trouble. The band was prolific in the underground scene of the 1970s, producing many demos and rehearsal tapes, but did not release a full-length album until reforming in the early 1980s with an almost completely new lineup. Throughout the band's history the only constant member has been vocalist Bobby Liebling. The revolving lineup of Pentagram has featured many well respected musicians in the local doom metal scene, with members spending time in other acts such as the Obsessed, Place of Skulls, Internal Void, Spirit Car