They say opposites attract. In music, when sounds foreign to one other collide to form single cohesive tracks, we often call the results "mash-ups." To some, these are musical dreams; others see them as ear-opening opportunities to let different artists into their lives. Recently, rap royalty Queen Latifah and country legend Dolly Parton embarked on the ultimate odd pairing, joining forces in the film 'Joyful Noise.' To celebrate their sonic union, The BoomBox compiled a list of the 10 best unlikely collaborations involving rappers, singers, rockers and shocking entertainers. Grab a turntable and electric guitar and check them out.

10. Public Enemy & Anthrax
Paul Natkin, WireImage

As Public Enemy led the charge for socially conscious hip-hop, the music carried boatloads of angst. 'Bring the Noise' was a perfect fit for heavy metal outfit Anthrax, who jumped on the song and literally brought the noise. The initial pairing happened because Chuck D saw Anthrax's Scott Ian wearing a Public Enemy T-shirt while performing. The track was recorded in 1991, and a joint-tour followed. Sounds like a match made in musical heaven.

9. DMC & Sarah McLachlan
Getty Images

At one point in his life, DMC of Run DMC suffered depression and contemplated suicide. Then he heard Sarah McLachlan's 'Angel,' a song he said saved his life and inspired him to write his autobiography. While researching the book, he learned that he was adopted, and after approaching McLachlan at a Grammy party to thank her for saving him through music, the two teamed up on 'Just Like Me.' On the track, which samples the '70s classic 'Cats in the Cradle,' DMC discusses learning of his adoption.

8. Pharrell Williams & Gloria Estefan

Pharrell, aka Skateboard P, is known for taking artists to new dimensions with his genius production, but when he met the legendary Gloria Estefan at a gym in Miami, who knew that he would help her start the next chapter in her career? With her recently released 'Miss Little Havana,' he did just that, and if the idea of mixing Estefan's salsa-infused dance sound with P's hip-pop instrumentals initially seemed strange, the finished product makes perfect sense.

7. Redman & Christina Aguilera
Mark Allan, WireImage

In 2002, with the early hit 'Genie in a Bottle' behind her, Christina Aguilera aimed to show the world her seductive side. Of all the artists to align with, she picked Dirty Jerz rap veteran Redman to help her accomplish this goal. Their song 'Dirrty' definitely lived up to its title, as Xtina displayed her sexiness all over the track. Couple that with Red's gruff delivery, and the result was a risque pop-meets-rap party. Christina definitely erased her clean image with the song.

6. Kanye West & Adam Levine
Getty Images

Nowadays, Kanye could do a song with the Dalai Lama, and no one would think it strange. However, this wasn't the case in 2005, when Yeezy brought Maroon 5's Adam Levine on board for the pensive 'Late Registration' track 'Heard Em Say.' Like Kanye, Maroon 5 were just starting to become a force in their genre. The song introduced each artist to the other's world. Now Maroon 5 is working with rappers, and Kanye is working with anyone.

5. DMX & Marilyn Manson
Jason Kempin, FilmMagic | Theo Wargo, WireImage

DMX may have shortened his name from Dark Man X, but the seriously gloomy undertones never really left his brand. After his debut, 'It's Dark & Hell Is Hot,' he returned with 'Flesh Of My Flesh, Blood Of My Blood.' Since the cover showed X with blood all over his body, it was only natural that the leader of fright-rock band Marilyn Manson would assist on 'The Omen,' the second part of the 'It's Dark' track 'Damien.' The song is, in a word, creepy.

4. Run DMC & Aerosmith
KMazur, WireImage

The song that started it all. In 1986, Run DMC was in the process of pioneering hip-hop, while Aerosmith were pioneering the next phase of rock. The two joined forces for 'Walk This Way,' appearing in a video that showed the two bands originally not getting along and later coming together to perform. This song broke down the boundaries that existed between genres early on, proving that anyone can come together in the interest of sonic teamwork.

3. Jay-Z & Chris Martin

The further Jay-Z's career has progressed, the more comfortable he's become straying from thematic rap formulas and topics. By 2006's 'Kingdom Come,' Hov had reached a comfort zone in terms of mixing different sounds. He aligned with Coldplay's Chris Martin -- now one of his best friends -- for the song 'Beach Chair.' The track found Jay reflecting on his own legacy and considering the impact he wants to have on his children. Now, thanks to Beyonce, he has a little girl to share that with.

2. Nelly & Tim McGraw

From the day we met Nelly, he's flown his country flag high. Still, the combination of rap and country music never seemed like a possibility -- even for the 'Country Grammar' rhymer. Then came Nelly's collaboration with Tim McGraw on 'Over and Over.' On paper, the song promised to be a disaster, but it actually worked. Nelly's sing-songy rhymes backed by McGraw's smooth vocals made this song a win for folks scared off by either genre, and both artists won new fans.

1. Eminem & Elton John

Throughout the '90s, Eminem was known for spouting anti-gay musings in his songs, among other reckless things, but with 2000's 'Stan,' his dark track about a crazed fan, he showed a more contemplative side. He got emo-pop siren Dido to sing the hook, and then he pulled the ultimate move, enlisting Elton John to perform the song with him at the 2001 Grammy Awards. It was a historic moment, as it showed Eminem side by side with an openly homosexual music legend. The two went on to form a friendship, and John even helped Eminem quit drugs. One fateful performance turned into a life-saving experience.

Watch 'Eminem Is One of the Most Popular People on Facebook'

#fivemin-widget-blogsmith-image-686891{display:none;} .cke_show_borders #fivemin-widget-blogsmith-image-686891, #postcontentcontainer #fivemin-widget-blogsmith-image-686891{width:476px;height:357px;display:block;}
10 Most Popular People On Facebook

Follow @theboombox on Twitter | Like Us on Facebook | Sign Up for Newsletter