Elton John has opened up about his unusual relationship with Eminem ahead of his new Beats 1 radio show.

The show was part of Elton's "Rocket Hour," which began airing in 2015 and the segment about Eminem is set to air this week.

"Eminem just did a show in which Drake introduced him in Detroit as 'the greatest rapper of all time,'" John said.

"It's very hard to disagree with that. I love him, and he's a dear friend."

During the show he also revealed plans for a new tell-all autobiography in the works.

"I'm not prone to being a nostalgic person," John said in a statement that accompanied the announcement.

"I'm often accused of only looking forward to my next gig or creative project.

It's come as quite a surprise how cathartic I am finding the process of writing my memoirs.

As I look back, I realize what a crazy life I have had the extreme privilege of living."