"Me and [son] Martin [Davies] had been thinking about it for a while," Davies tells Radio.com. "We did a film called Mystical Journey a few years ago � about my spiritual interests, and all my alternative ideas about the world and life. So, we thought we'd do a similar thing about rock 'n' roll, and the journey of being in a rock 'n' roll band on the road. We want to interview old colleagues, other celebrities and fans."