Jay-Z fears he is growing too old for hip-hop.

The '99 Problems' hitmaker admits he is aware that most artists in the genre are under 30, and as he approaches 40, staying relevant is harder - unless audiences change.

He said: "Hip-hop saved my life. When someone does something for you, it's only right you repay that tenfold, and that was what hip-hop did for me. How could I not protect that or leave it in a good place for the next generation?

"The reason you turn off the hip hop as you mature is because there's not enough of what you're going through in your life currently. There's not a lot of people who have come of age in rap because it's only 30. As more people come of age, hopefully the topics get broader and then the audience will stay around longer.

"But it's so much viewed as a young person's sport right now at this present moment that it's very difficult. You want to get on the radio, and you've got to make a jingle that's catchy, that sounds like everything else that's on the radio. Not me, the other guy."

The rapper - real name Shawn Carter - says he knows he has to continue to try new things and reinvent himself in order to maintain his popularity.

He added to Scotsman.com: "Hip-hop is about the gift of discovery. It's who has the newest sneakers, who has the new pants.

"So if I go to school with Jay-Z on my iPod, they go, 'OK, we all know him.' You have to come to school with some new band that no-one else has heard of. As an artist you're fighting against everything that's new. So not only are you swimming upstream, you have someone pulling on your leg: the new guy, the weight of the new guy.

It's like a crowded hallway full of people and you have to walk against it. Some don't make it to the end of the hall. You're always in the way. You have to be built for competition."