Six Collaborations More Out There Than Justin Bieber And Ludacris

Yesterday, the latest movement in 15-year-old Canadian phenom Justin Bieber's crusade to take over the pop airwaves premiered online. "Baby" debuted on Monday and quickly shot up the iTunes sales chart (it currently sits at #2, just behind Ke$ha's seemingly indestructible "Tik Tok"). The most notable aspect of the tune is the guest spot from Atlanta rapper Ludacris, who drops a verse about his own first love.

Though Bieber is training under the expert tutelage of Usher, it's still a relatively unexpected tag-team, as Bieber's sweet take on R&B doesn't seem like it would gel well with Luda's usually ribald delivery. However, the track works amazingly well, and it joins the pantheon of excellently weird team-ups between rappers and ... non-rappers.

Mudhoney and Sir Mix-A-Lot

The soundtrack to the 1993 film "Judgment Night" revolved around a single concept: Pairing rock bands with rappers, sometimes with hilarious results. While just about all the entries on the album are confusing in one way or another (Helmet and House of Pain, Sonic Youth and Cypress Hill), the title of most jaw-droppingly weird team-up goes to Mudhoney and Sir Mix-A-Lot, who hooked up on a song called "Freak Momma." Sure, both were from Seattle, but the similarities pretty much ended there. It's not a bad song, but it just sounds so ... odd.

Kenny Rogers and Wyclef Jean

Clef's second solo album The Ecleftic: 2 Sides II a Book was full of bizarre guest spots (including those from Dwayne "The Rock" Johnson and Earth, Wind and Fire), but none sounded stranger than Kenny Rogers' drop-in on "Kenny Rogers - Pharoahe Monch Dub Plate," which brought together Rogers' "The Gambler" and Monch's "Simon Says" for one of the weirder tunes in the mash-up era.

Jesse McCartney and Fabolous

McCartney has also worked with the aforementioned Ludacris, but he welcomed Fabolous to a remix of his tune "She's No You." The remix, helmed by the Neptunes, is pretty tight, and it's a surprisingly spry verse from Fabolous. But as soon as McCartney's vocals kick in, it sends the tune to another planet.

Tim McGraw and Nelly

The single "Over and Over," from Nelly's 2004 album Suit, was a gigantic hit (it peaked at #3 on the Billboard Hot 100), but it never sounded any more natural for one of the biggest names in country music to team up with the original St. Lunatic.

Coldplay and Jay-Z

Two of the biggest names in music teamed up for "Lost!" last year. But despite the killer verse from Jay-Z, Coldplay didn't sound any funkier.

Phil Collins and Lil' Kim

In what might be the greatest musical collaboration of all time, Phil Collins teamed up with Lil' Kim for a version of "In the Air Tonight," which was on an album completely devoted to hip-hop versions of Collins tracks. The results are predictably staggering. Sadly, that album only came out in Germany, but floats around the Internet like a musical Yeti.

What's your favorite left-field guest spot from a rapper? Leave your thoughts in the comments or tweet us @mtvnews.