The Van Halen that Sammy Hagar left in 1996 wasn't the same as the one he returned to in 2004.

On June 11, 2004, Hagar and his former bandmates reunited onstage for the first time in nearly nine years. Since the singer fired or was quit — depending on who you believe — on Father's Day 1996, Van Halen had endured some difficult times.

First, they attempted a studio reunion with their original frontman David Lee Roth, which flamed out spectacularly and in full view of the public at the MTV Music Awards. Then they recruited Extreme's Gary Cherone as their third lead singer, which resulted in 1998's poorly received studio album Van Halen III and a tour that failed to light up the box office to their normal high standards. Cherone was dismissed in 1999, and Van Halen all but vanished for the next five years.

Hagar had stayed busy since the split, releasing four new studio albums between 1997 and 2002 and touring heavily — including a drama-filled co-headlining trek with Roth. His output undermined Alex and Eddie Van Halen's claim that Hagar's shoddy work ethic was partly to blame for his departure from the group.

Initially intending only to rekindle their friendship, Hagar reached out to Alex Van Halen in 2003, which soon led to the recording of three new tracks for the band's career-spanning The Best of Both Worlds compilation album and plans for a summer 2004 tour.

Hagar returned to a group that was more focused on showcasing its entire career. After including only the most undeniable songs from the Roth years ("Jump," "Panama," "Ain't Talkin' Bout Love" and their cover of the Kinks' "You Really Got Me") at live shows during Hagar's decade in the band, Van Halen brought fan favorites such as "Mean Street" and "Dance the Night Away" back during their 1998 tour with Cherone.

That trend continued on opening night of the 2004 tour, which included six Roth-era songs. In addition to the four songs mentioned above, Hagar handled lead vocals on the Fair Warning gem "Unchained," while bassist Michael Anthony (with eager backing support from Hagar) took on Van Halen II's "Somebody Get Me a Doctor."

Read More: Every David Lee Roth-Era Van Halen Song Sammy Hagar Sang

Oddly for a Hagar reunion tour, the show began with the biggest hit of Van Halen's Roth era, "Jump." They also stopped playing full-band renditions of Hagar's solo hits. On previous tours, they had teamed up to play "I Can't Drive 55" and "There's Only One Way to Rock," with the latter featuring a show-highlighting guitar duel between Hagar and Van Halen. On the 2004 trek, Hagar only offered solo acoustic renditions of his songs "Where Eagles Fly" and "Deeper Kinda Love."

In an admirable but ultimately misguided attempt at showcasing their newest material, Van Halen played all three of the new songs from The Best of Both Worlds compilation — "Up for Breakfast," "It's About Time" and "Learning to See" — on opening night. These songs didn't exactly stand the test of time, and their inclusion meant the exclusion of Van Hagar-era concert favorites such as "Summer Nights," "Finish What Ya Started" and "Love Walks In." ("Learning to See" was dropped after 12 shows and replaced with Balance's "The Seventh Seal.")

Watch the Opening Night of Van Halen's 2004 Tour

The 2004 Tour Was a Disastrous End to Van Halen's Sammy Hagar Era

Unfortunately, due to lingering personality conflicts and Eddie Van Halen's worsening addiction struggles, Van Halen's Best of Both Worlds tour quickly descended into turmoil and ended just short of disaster. In his 2011 book Red: My Uncensored Life in Rock, Hagar said that a potential $5 million penalty was the only thing keeping him from quitting after four shows.

“I was just hoping it was going to be great and everybody was going to be happy and a big love fest and just go at it again," Hagar told NBC in 2011, "but it wasn’t that at all. It was the complete opposite."

Neither Hagar nor Anthony performed with Van Halen again after the tour's final show on Nov. 19, 2004, in Tucson, Arizona. In 2007, Van Halen reunited with Roth and recruited Eddie's son Wolfgang to take over bass duties for a highly successful tour. This lineup would mount two more such tours and release the 2012 studio album A Different Kind of Truth prior to the guitarist's death in 2020.

Van Halen June 11, 2004 Greensboro, S.C. Set List
1. "Jump" (From 1984's 1984)
2. "Runaround" (From 1991's For Unlawful Carnal Knowledge)
3. "Humans Being" From 1996's Twister Soundtrack)
4. "Up for Breakfast" (From 2004's The Best of Both Worlds)
5. Bass Solo
6. "Somebody Get Me a Doctor" (From 1979's Van Halen II)
7. "Poundcake" (From 1991's For Unlawful Carnal Knowledge)
8. "It's About Time" (From 2004's The Best of Both Worlds)
9. Drum Solo
10. "Top of the World" (From 1991's For Unlawful Carnal Knowledge)
11. "Unchained" (From 1981's Fair Warning)
12. "Why Can't This Be Love" (From 1986's 5150)
13. "Eagles Fly" (From 1987's I Never Said Goodbye)
14. "Deeper Kinda Love" (From 2000's Ten 13)
15. "Learning to See" (From 2004's The Best of Both Worlds)
16. "Best of Both Worlds" (From 1986's 5150)
17. Guitar Solo
18. "Dreams" (From 1986's 5150)
19. "Ain't Talkin' 'bout Love' (From 1978's Van Halen)
20. "Right Now" (From 1991's For Unlawful Carnal Knowledge)
21. "You Really Got Me" (Kinks cover from Van Halen)
22. "Panama" (From 1984's 1984)
23. "When It's Love" (From 1988's OU812)

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Gallery Credit: Matthew Wilkening, except as noted below.