Traditional heavy metal, also known as classic metal or often simply heavy metal, is a recent umbrella term describing bands and artists who play a metal music style similar to the style heard before the genre evolved and splintered into many different styles and subgenres. It is characterized by mid-to-fast-tempo riffs, by thumping basslines, crunchy riffs, extended lead guitar solos, and clean, often high-pitched vocals and anthemic choruses. It is not generally categorised as a subgenre of metal, but the main genre of it. Examples include Led Zeppelin, Deep Purple, Black Sabbath, Judas Priest, and Iron Maiden.