Heavy metal developed in the late 1960s in the UK and US, with roots in blues rock. It has a thick, amplified sound characterized by distorted guitars, extended solos, loud drums and vocals. Early influential bands included Led Zeppelin, Deep Purple, and Black Sabbath. In the 1970s, Motörhead introduced punk elements and bands like Iron Maiden played a similar style. By the 1980s, underground extreme styles like thrash metal emerged with Metallica and Megadeth, while death metal and black metal remained subcultural. Heavy metal is traditionally characterized by loud distorted guitars, powerful rhythms, dense bass and drums, and vigorous vocals centered around the electric guitar.