The thrash icons endured a challenging time while the record was in production, after falling out with Bush in the aftermath of a failed reunion with Joey Belladonna.

They hired Dan Nelson as new frontman and he completed work on his version of Worship Music - but he was dismissed before its release, leading to Bush's temporary return.

Now he's offered another reason for his second departure in 2010, which paved the way for Belladonna's return and the release of the album with his vocals the following year.

Bush tells Mitch Lafon: "I didn't participate in anything, and I always had on previous records. It was just the mindset of, 'Nah, no.' I even said, 'Okay, if you pay me this amount of money, I'll do it.' Because I wasn't doing it out of the love of my soul - I was doing it for another reason.