Eminem wanted to ''impress'' Rick Rubin with his new album.
The 'Berzerk' hitmaker felt ''honoured'' when he heard the famed producer was keen to work with him and was ''nervous'' when they first entered the studio together to record his new album 'The Marshall Mathers LP 2'.
He said: ''My manager Paul had been talking to him and Rick had expressed he had an interest in working with me. When Paul brought it to my attention I was super excited, just honoured at the fact that he was even thinking about it.
''I had my reservations because I felt like - I'm a super fan of Rick - so I'd probably be a little nervous.
''I don't know what the vibe would be just because I would be wanting to impress him. It was kinda like the feeling I got early on with Dre.
''I had never met him, so I was like nervous to meet him and even more nervous to work with him.''
The album opens with 'Bad Guy', a follow-up song to his classic hit 'Stan', which tells the tale of the original protagonist's little brother and Eminem was thrilled to be able to revisit the story once he had the right music.
He told BBC Radio 1 DJ Zane Lowe: ''I had heard a lot of chatter right that I should do 'Stan 2'.
''All I kept thinking was 'Well, Stan's dead', he died in the story, when in the back of my mind I kinda had an idea of who could be left from the story but I needed to get the right beat.
''As soon as I heard the words to the chorus, the beat was sent to me, it had those words on it. I like making my own choruses, but it's also fun for me to take someone else's words and interpret them in my own way.''