On his new album, Love Story, due out on Apr. 21, Yelawolf has only one feature: Eminem.

It makes sense that Em would appear on the album -- he executive produced the project, and Yela is signed to his Shady Records -- but why did the Alabama rapper decide to ask the Rap God to hop on "Best Friend" specifically?

"The song was already really strong, and I knew that I was touching on something that was serious -- or, to me, it was," Wolf explained to MTV News on Friday. "The melody in the song, it came together, and I just thought, If Marshall, if he gets on this and understands this concept, that it would be outta here. So I just crossed my fingers and sent it to him. Luckily, he understood it perfectly, and obviously killed it."

This isn't the first time the two have collabed -- we heard them together on Yela's last album, Radioactive, for instance. But that track, "Throw It Up," had a decidedly different vibe than "Best Friend." The song, which also features Gangsta Boo, showcases the two Shady MCs delivering frenetic verses packed with double-time flows.

"Best Friend," though, has a more ambient sonic tone, and features Yela not spitting the quick-tongued bars he shown capable of, but singing his verses and the hook. Em, though, still resorts to the rapid rhymes. It creates a contrast in their styles for this particular record.

"It's the perfect record for him and I for this album," he added. "Because its me standing my own ground creatively and where I'm at on it creatively, and Marshall being Marshall. To not rap -- I thought it created a really cool vibe, and no one's heard us like that musically, and content-wise no one's heard that, either."

They've also already worked on the video, which Yela promises will be a treat.

"This video is the most cinematic video I've ever shot," he said. "It was myself, Marshall, and a wolf -- two humans and a wolf [are] the only people you see in this entire video."

Yela's Love Story hits stores on Tuesday.