In contrast to its large pop music output, Sweden has a most prolific death metal scene. Gothenburg is known for a "melodic death metal" sound. Many bands from there, such as In Flames, Dark Tranquillity, At the Gates, The Haunted, as well as Stockholm's Amon Amarth and Opeth have seen increased commercial success in Europe and the United States. Melodic death metal is a broad genre with many variations, but has roots in traditional death metal, black metal and classic metal such as that of Iron Maiden. Still, many bands are influenced by genres as broad as Swedish folk music, alternative music, electronica, gothic music, progressive music and even neo-classical music. Sweden is known in the extreme metal community for its late-80s to early-90s death metal scene, spawning bands like Entombed, as well as more obscure, "brutal" bands like Repugnant and Treblinka (later called Tiamat).