Mark Ronson isn't worried about his 40th birthday.

The 39-year-old music producer will hit the milestone in September this year but insists he's not bothered about falling into the middle-aged bracket and doesn't believe his age will affect his music.

When asked if he's concerned about turning 40 and having a mid-life crisis, he said: ''No, no. I mean, I've just bought a convertible Porsche ... I feel OK about it [hitting mid-life]. After 35, everything sounds old in music anyways, so it's fine.''

However, the talented musician has already thought about his future and tries to create music that will still be successful in two decades time.

Asked what his ultimate ambition is, he told Australia's Marie Claire magazine: ''To leave a legacy of great records and good music. I don't want anything much grander than that...

''I try to make music that you could imagine hearing in 20 years. There is no specific ingredient, but I have no problem saying I'm really influenced by and love soul music. Stuff like Motown probably filters into the things I do. But you want to make a record that sounds timeless.''