The genre of heavy metal (or simply metal) is a subgenre of rock music that developed in the late 1960s and early 1970s, largely in the United States and the United Kingdom.

[1][2][3] With roots in blues rock and psychedelic rock, the first heavy metal bands such as Black Sabbath and Deep Purple attracted large audiences, and during the late 1960s and mid-1970s these bands and others in their genre were featured at a number of historic rock festivals.

[4] Judas Priest helped spur the genre's evolution by discarding much of its blues influence.

[5][6] After the genre fused with other related genres such as punk rock in the late 1970s, bands in the new wave of British heavy metal such as Iron Maiden and Saxon followed in a similar vein.

The following is an incomplete list of traveling metal festivals, both active and defunct: