40 years ago today (May 29th, 1983), Van Halen, Scorpions, Triumph, Judas Priest, Ozzy Osbourne, Mötley Crüe, and Quiet Riot appeared on one bill in front of nearly 500,000 people for "Heavy Metal Day" at the legendary US Festival, held at Glen Helen Regional Park near Devore, San Bernardino, California.

Spearheaded by Apple Computer co-founder Steve Wozniak, the US Festival was intended to be a celebration of technology and culture, with a temporary stage and open-air venue paid for by Wozniak himself just for the purposes of the festival.

In celebration of Memorial Day, SPIN.com has published an extensive article looking back at the festival. The following excerpt focuses on Day 2: “Heavy Metal Day”....

There was no momentum lost on Day 2 – appropriately dubbed “Heavy Metal Day,” because its lineup was pretty close to being a Reagan-era hesher’s wet dream.

The day kicked off at high noon, with Sunset Strip breakout stars Quiet Riot and Mötley Crüe performing back-to-back. They were followed by British metal icons Ozzy Osbourne and Judas Priest before more international heavy-hitters in Triumph (Canada) and Scorpions (Germany) took the stage. And Wozniak secured Van Halen, a band that was seemingly designed in a lab to host the biggest rock and roll party in SoCal history, to close out the day.

Gil Moore (drummer/co-vocalist, Triumph): "Any band on Heavy Metal Sunday could sell out an arena in California. When you add them all together, you went, ‘holy smokes.’ It was a powerful card."

Building this lineup cost Wozniak a pretty penny. He shelled out a million bucks for Van Halen, which was busy working on its tide-shifting 1984 album, to headline Heavy Metal Day. That payday later ballooned to $1.5 million, though, thanks to the addition of David Bowie and a shrewd contractual move by Van Halen manager Noel Monk.

Michael Anthony (bassist, Van Halen): "We had a most favored nations clause in our contract, which meant we couldn’t make less than anybody else made."

Barry Fey (Promoter): "David [Bowie] [told] me, ‘We’ll have to interrupt our tour and charter a [plane] to bring our equipment and get it right back again.’ So I went to Steve [Wozniak], ‘David’s gonna cost you a million and a half, but it’s gonna cost you an extra half a million for Van Halen.’ He just shrugged his shoulders: ‘So?’" (From The Forgotten Festival in OC Register, 2012.)

Noel Monk (Manager, Van Halen): "You don’t say no to that kind of offer. I mean, you can’t." (From his 2017 book, Runnin’ With The Devil).

Anthony: "It was pretty crazy. But at that time, we loved playing to big crowds. And the outdoor festival thing was really big back then. So yeah, we were really excited to do it. Obviously, the financial part worked out. Just being on a show with all those acts – we always loved doing that kind of thing."

Wozniak and Fey, meanwhile, were busy putting the finishing touches on Heavy Metal Day in the weeks – and in some cases, days – leading up to the festival.

Mike Levine (bassist/keyboardist, Triumph): "Wozniak flew up to Toronto and took us to dinner. We had a bit of an issue we were concerned about – our last play in Los Angeles had been a co-headliner with Journey at the Rose Bowl. And we were due for an indoor play in the L.A. area, so we also had the choice of playing a couple or three shows at the Long Beach Arena or doing the US Festival. And we’re like,’What the hell do we do with this festival thing? It’s going to be sensational because it’ll be a part of history. But we could end up blowing up the L.A. market for ourselves.’ But it was one of those things where we just felt that it’s better to be a part of history."

Rudy Sarzo (bassist, Quiet Riot): "Quiet Riot was on tour with the Scorpions. We shared the same agency, and they were playing a three-week warmup tour for the US Festival. We did that little tour with them, and the last day of their tour was in Denver. And Barry Fey happened to be backstage, and after our set, he runs in and introduces himself. He says, ‘Listen, we have a spot available for the US Festival. Would you guys be interested?’ And we said, ‘What is that?’ [Laughs.]. He explained what it was, we looked at each other, and our manager happened to be there, and we accepted it right there on the spot. This is two days before the show. Logistically, we had to scramble to make it happen. It meant we had no road crew for the US Festival because our crew was driving our rented U-Haul truck to our gig the day after the US Festival in Detroit."

Read the full report at SPIN.com.