Slash was scared to call up stars and ask them to guest on his solo record.

The former Guns 'N' Roses guitarist is set to release his debut solo album - which features a range of singers including Iggy Pop, Ozzy Osbourne and Fergie from the Black Eyed Peas - but said he was uncomfortable when it came to calling up people to ask if they'd appear.

He said: "The motivation was there but also it took all these years to collect enough credibility to call up a guy like drummer Steve Ferrone and say, 'Hey, would you come down and play on a track?' It was nerve wracking just to make the phone calls and see whether they would do it or not."

Slash also told how he knew the time was right to make a solo record after the singer from his band, Velvet Revolver, Scott Weiland, was fired because of disputes with other members.

He added: "It was a perfect time to do it because Velvet, at least with Scott, had run its course. I couldn't go through that process of auditioning singers and get that all back together to do another Velvet record. I really needed a break from the band vibe."

He also said this leant him a freedom to experiment musically, and try out styles he hasn't been able to at other points in his career.

Slash said: "I had this one idea that was this fast metal riff, and that's something I've always wanted to do. I'm a huge Megadeth and Metallica fan and I can't do it in Velvet and it definitely wasn't gonna happen in Guns 'N' Roses. I was like, 'Let's give it a shot and see what happens'."

'Slash' is released worldwide from April.