Rap superstar Kanye West is "conflicted" about living in the world of celebrity, says friend and collaborator John Legend.

West has produced each of Legend's solo albums which has led to a burgeoning friendship over the years.

In an upcoming interview for 'Oprah's Next Chapter,' Legend revealed what Kanye is like behind the scenes.

He explained: "I think a lot of who he is in public is who he is. He's not afraid to tell the truth... He's bold. We obviously have very different personalities. You've heard him talk about the celebrity aspect of his life and the fame, and he acknowledges that he's in this world. But he's also conflicted about it. You can tell through his art and through the things he says."

He continued: "People don't always see the generous side of [Kanye]. They don't always see the guy who's been working with me and contributing to my work for over 10 years. They don't necessarily see all of that in public, and I see that."

Meanwhile, West is celebrating his 36th birthday today (June 8).

His girlfriend Kim Kardashian took to Instagram today to post a photo collage of the pair with the accompanying message: "Happy Birthday to my best friend, the ❤of my life, my soul!!!! I love you beyond words! (sic)."