When Jay-Z and Eminem take the stage in Detroit at Comerica Park on Thursday and Friday and again in New York at Yankee Stadium on September 13 and 14, it be a meeting of two of the biggest names in rap, who between them have sold more than 120 million albums.
But their pairing is just the latest mega-coupling in the history of tours that promised to bring together the best of both worlds (sorry, Jay and R. Kelly, we tried not to bring that one up).
Among our favorites:
Guns N' Roses and Metallica
This volcanic 1992 outing featuring the biggest rock band in the world and the thrash legends who would soon snatch that crown was every bit as explosive as anticipated. With unpredictable act Faith No More in the opening slot (after Nirvana reportedly declined), the three-month stadium tour featured plenty of drama, including Metallica singer James Hetfield suffering second- and third-degree pyro burns during a show in Montreal, which turned into a riot after Guns singer Axl Rose left the stage complaining of a sore throat.
Wu-Tang Clan and Rage Against the Machine
At the height of their powers in 1997, bomb-throwing Los Angeles rockers Rage teamed up with the equally incendiary rap crew for what was slated to be a triumphant tour of amphitheaters and arenas. But in a sign of how shook Rage had the authorities, police in a number of cities tried to get the shows canceled fearing Rage's alleged "anti-law-enforcement" stance, to no avail. Due to internal pressure within the sometimes-fractious Wu-Tang, some missed shows and an alleged assault, the Clan dropped off after less than two weeks of shows, replaced by the Roots and Foo Fighters.
Justin Timberlake and Christina Aguilera
The Justified/Stripped Tour may go down as the last hurrah of the teen-pop era. The 2003 joint tour between the former 'NSYNC legend and the pop diva was a high-tech, big-budget extravaganza that found both singers at the peak of their powers.
Eminem, 50 Cent, Lil Jon, G-Unit and D12
It was a rap monster, with the Slim Shady and 50 headlining the Anger Management 3 amphitheater outing that would mark the last full-fledged tour by Eminem in the past five years. Marshall Mathers would end up canceling the European leg of the tour in order to check into rehab for a prescription-medicine addiction.
There are plenty of others, too, many of them on the classic-rock tip, including the unlikely pairing of two former Van Halen singers, David Lee Roth and Sammy Hagar, in 2002; the 1995 pairing of Neil Young and Pearl Jam; and the ongoing collaboration between the world's leading piano men, Elton John and Billy Joel.
History is also filled with tours that never happened that were as exciting on paper as some of the ones that have, including the scotched dual-headlining Fame Kills extravaganza promised by Lady Gaga and Kanye West last year. That eye-popping spectacle was grounded after West went into hiding following his bum-rush of Taylor Swift at the MTV Video Music Awards. Then there was the Big Four Tour featuring Metallica, Megadeth, Slayer and Anthrax that has reportedly been brewing for two years but has yet to happen. Instead, it turned into this year's American Carnage Tour with Slayer, Megadeth and Testament.
What is your favorite superstar bill? Let us know in the comments below!