Kid Rock was made a better singer by Rick Rubin.

The 'Mr Rock 'n' Roll' singer was pushed in the studio by his producer, who made him sing in keys much higher than he was used to.

He said: ''He really forced me to sing in higher keys than I did on [2010 album] 'Born Free'. We just kept running the capo up the guitar neck and I was straining, and he said, 'Trust me, you're such a good singer, you need to be pushed. And if you sing in these keys for the next couple of years, you're going to become a great singer.' And lo and behold, the f***er was right again.''

Kid has a track on his new album, 'Rebel Soul', called 'Let's Ride', which is dedicated to US troops, and he says he wrote it as a rocking tune to counter all the maudlin country songs that get written for them.

He added to Classic Rock magazine: ''I travel all over playing for our troops. I got to see and hear a lot and talked to a lot of people embedded in the world, and they get a lot of hokey country songs written for them. I thought I'd write something hard and heavy but still melodic, and it's not f***ing politically correct. But to get them jacked up when they go out to do the dirty work, something they can be proud of.''