Shepherd tells how, as a boy, he told his stepfather he wanted to be a musician, and was presented with a large book of chords. And all he had to work with was a disconnected guitar neck.

The bassist explains: "My stepdad said, 'Okay, if you can learn every chord in this book I'll get you a guitar.' So I did; I sat down with a neck - no strings, nothing, just a neck - and I learned every chord possible out of that book. And I got a guitar."

His passion for just playing has never diminished, he admits. "It took me until we reunited to find that Kim Thayill wrote Superunknown with Chris Cornell," Shepherd says. "I thought that was just a Chris riff. I never paid any attention; I was just like, blaring guitars, 'Alright, let's play!'"