WANTAGH, New York — When a guy in the next row throws up on the seat in front of him and passes out on it, and when two girls 10 feet away lift their tops and make out, and it all happens before 7 p.m., you know you must be at Ozzfest.

Metal's annual all-day summer ritual Wednesday at the Jones Beach Amphitheater was once again a bacchanalia of volume and decadence that left thousands dazed and amused, and fortunately the excitement onstage eclipsed the action in the crowd. But while prior years mostly celebrated the then-current faces of metal, Ozzfest 2004 is more like a history lesson, which means that the lineup is the heaviest and least commercial yet.

Heavy Metal 101 was highlighted with a lesson from headliners Black Sabbath, a band that surfaced in 1970 as a vitriolic antidote to flower power and virtually birthed the metal genre. Sabbath opened with "War Pigs," during which they compared projected images of the Vietnam War and World War II with shots of the war in Iraq. Ozzy Osbourne toddled from one side of the stage to the other and roused the crowd by jumping up and down, wriggling his fingers in the air, clapping his hands above his head, baring his teeth and shouting his trademark motto: "Go f---ing crazy!" His bandmates provided oppressive, stark cathedrals of sound as they ripped through doomy classics like "Black Sabbath" and "NIB" and more upbeat tracks including "Fairies Wear Boots" and "Paranoid."

Inspired by the aggression of Black Sabbath and the virtuosity of Led Zeppelin, Judas Priest rose up against tepid '70s radio rock and the harsh, industrial climate of Birmingham, England, to pioneer a movement known as the new wave of British heavy metal. The band reigned well through the '80s, but Priest's enthusiasm and appeal waned after singer Rob Halford quit in the early '90s. Now, he's back in the band, and Priest seem as primed and charged as the motorcycles Halford rides onstage during "Hell Bent for Leather."

MTV News Tour Reports.

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