Glam metal is a sub-genre of heavy metal music that arose in the late 1970s - early 1980s in the United States. It was a dominant genre in popular rock music throughout the 1980s and early 1990s.[citation needed] The genre is also referred to, often by detractors, as hair metal. This term was popularized by MTV in the 1990s and derives from the tendency amongst most bands to style their long hair in a teased-up fashion. During its heyday, the genre was often referred to as heavy metal or simply metal.