Axl Rose claims the "source of all the insanity" in his life is his voice.

The volatile Guns 'N' Roses singer - who is renowned for keeping fans waiting for hours past stage time before starting a performance, and is prone to aggressive outbursts - blames all his wild antics on the way he has to sing, according to his friend and touring partner Sebastian Bach.

Sebastian explained to US radio station 94 WYSP in Pennsylvania: "Everybody has all these theories as to why he acts the way he acts. And there's no big mystery. He tells me the source of all of the insanity - it's his voice.

"It's his job to sing like that, and sometimes that sound is hard for him. To sing in that range is just not an easy thing to do. And if it takes him forty-five more minutes to warm up his pipes so he can sing 'Sweet Child O' Mine' -then, you drive around in your car and put on Guns 'N' Roses and just go for it."

Guns 'N' Roses present European tour has been beset with problems, with the band's taking to the stage late because Axl, 48, was asleep then having the sound cut in Reading, England after their set ran past a curfew, and the group were further bottled offstage in Dublin, Ireland, after they started a show an hour late.

Meanwhile details of Guns 'N' Roses backstage requirements have been revealed, with a number of very specific items, including a room for Axl to sleep in containing a bed, a sofa, a coffee table, six lamps and a rug. This room must also be decorated with 18 red and 18 white fresh roses.