Kanye West, Jay-Z Watch The Throne Pairing Treads New Ground

Album collaborations are rare in hip-hop history.

Now that their first single, "H.A.M.," has debuted, it looks like Jay-Z and Kanye West's highly anticipated Watch the Throne album is actually happening.

West tweeted about the collaboration in August, and confirmed it a few months later, saying the project would now be a full album. But few would have guessed it would be released so soon — right on the heels of West's critically lauded My Beautiful Dark Twisted Fantasy — and there aren't too many examples in music history of two superstars collaborating on an album.

Click for photos of other great collaborations in music history.

There have been plenty of rock "supergroups" who have released albums over the years, starting with the likes of Cream (Eric Clapton, Ginger Baker and Jack Bruce) and Crosby, Stills and Nash (David Crosby, Stephen Stills and Graham Nash) in the 1960s and continuing to Velvet Revolver (Slash, Scott Weiland, Dave Kushner, Duff McKagan and Matt Sorum), Them Crooked Vultures (Dave Grohl, Josh Homme and John Paul Jones) and Audioslave (Chris Cornell, Tom Morello, Tim Commerford and Brad Wilk).

However, there isn't as rich a history of duos and groups coming together in hip-hop. The Wu-Tang Clan and N.W.A are as influential as any groups in hip-hop, but their members' reputations didn't flourish until they embarked on their own. And they were originally groups to begin with.

The Firm saw Nas join forces with AZ, Foxy Brown and Nature under the production of Dr. Dre and the Trackmasters, but besides Nas, the group's members are far from household names. More recently, Nas teamed up with Damian Marley to release Distant Relatives, but neither of these artists can touch the current popularity of West or Jay-Z.

Barbara Streisand enlisted Barry Gibb to write an album for her during the height of the Bee Gees' success in the late '70s. In 1980, the pair produced Streisand's Guilty, which went on to sell 20 million records and win a Grammy.

While anyone would be hard-pressed to match that success, Jay-Z is no stranger to collaborative albums. He teamed up with R. Kelly to record Best of Both Worlds in 2002. At the time, Jay-Z was arguably the most-popular rapper and R. Kelly was certainly the biggest R&B artist.

The two had previously collaborated successfully on Kelly's "Fiesta" remix and Jay-Z's "Guilty Until Proven Innocent," so an album seemed like the ideal next step. By time the album would be released, however, R. Kelly was embroiled in a very public trial.

The pair would try again with Unfinished Business in 2004, but tensions eventually boiled over. Amid their respective controversies, both albums were certified platinum.

Jay also collaborated with Linkin Park in 2004 to release Collision Course, which saw the group and Hov reworking and mashing up their previous recordings. Jay also unofficially collaborated with Danger Mouse on The Grey Album, a mash-up of Jay's The Black Album and the Beatles' self-titled White Album. The Grey Album would go on to launch the career of Danger Mouse, who has since released albums with Cee-Lo Green under the name Gnarls Barkley and The Shins' James Mercer as the band Broken Bells.

West produced the majority of Common's Be and Finding Forever albums, and he was rumored to be working with Pharrell and Lupe Fiasco on a CRS (Child Rebel Soldier) album.

Are you excited for Kanye West and Jay-Z to drop Watch the Throne? Tell us in the comments!