Sammy Hagar officially closed one chapter of his career and began another on Sept. 22, 1985, when he took the stage at the inaugural Farm Aid concert for a short set with his solo band that featured a special guest: Eddie Van Halen.

He joined Hagar for a blistering run through Led Zeppelin’s “Rock and Roll,” creating a memorable moment that took the crowd by surprise. Hagar and Van Halen had actually orchestrated it all before the event.

Hagar had already been recruited as Van Halen’s new lead singer. He would go on to front the band for over a decade, releasing four chart-topping albums before the collaboration flamed out in 1996.

“Eddie flew up to my house,” Hagar tells UCR. “I’d already went down and rehearsed with Ed, Al [Van Halen] and Mike [Anthony] at 5150 [Studios]. We were working on some songs, but we hadn’t really done anything. We had ‘Summer Nights’ and ‘Good Enough,’ but they weren’t finished. We had just jammed them. So Eddie flew up to my house in Northern California and he rehearsed with my band. I had a studio in my basement back then.

“He came out with us and he played a little guitar solo with two or three of his little pieces and then we went into ‘Rock and Roll’ and we rehearsed it,” Hagar continues. “That same day, Eddie and I wrote two or three more song ideas, and one of them never went anywhere. … It got bogged down with each record. The first two records really went fast, and then it bogged down. But the chemistry at the Farm Aid thing was phenomenal.”

Watch Sammy Hagar and Eddie Van Halen Perform ‘Rock and Roll’ at Farm Aid

Hagar recalls that the audience had no idea what was about to hit. “There was a classic picture in People magazine of Eddie standing there in his torn up jeans and his classic pose with his guitar neck up in the air, kind of leaning back a little bit, legs together, not far apart, that’s the way he used to stand – and me with my hand on his shoulder, and I jumped so fuckin’ high, my feet are about up to his shoulders and my hand is on his shoulder, so I’m way above him with my legs all tucked up. … It was a classic bad-ass shot, and it kind of said it all.”

Hagar still gets goosebumps when he thinks about that initial appearance with Van Halen, walking out in front of a crowd of 75,000 people. “The energy level between the two of us came way up, let me tell you,” he recalls. While they were onstage together, he announced that he would be the new lead singer for Van Halen, a moment that was both happy and bittersweet for Hagar.

“It was one of those double-edged swords,” he admits. “I was very excited about the music we had gotten together and made. When I was first asked to join Van Halen, I wasn’t that excited because I thought, ‘Eh, these guys, Eddie’s really great, but they’re party animals, and they’ve got kind of a weird image.’ To me, they were a little too showbizzy, and then when I met those guys, it was all Dave, you know? These guys were totally normal cats. They were party animals, but I could deal with that.

“When I announced that to my band, it was like their dicks went in the dirt,” he concludes. “It was really a tough thing for them, and it was tough for me. But I was excited, and it was an opportunity.”