Fans could be forgiven for wondering just how Iron Maiden's upcoming first-ever double album will sound in the wake of Bruce Dickinson's cancer battle. But bassist Steve Harris says their legendary frontman sounds "better than ever."

Harris told Kerrang! that The Book of Souls was largely finished before Iron Maiden announced in February that Dickinson had been stricken with a cancerous tumor on the back of his tongue.

“Bruce didn’t know and none of us knew anything about – there was no inkling of any of it,” Harris said. “He’d finished all his vocal bits completely anyway, and then there were some other bits and pieces we were doing. Really, we didn’t know anything. He didn’t show any signs at all. I mean, his singing, when you hear it – he’s singing better than ever.”

Iron Maiden said they delayed the release of The Book of Souls to allow Dickinson a fuller recovery. Now that doctors have given Dickinson a clean bill of health, they've set a release date for Sept. 4. For Harris, that's meant a welcome refocus on the band after a period of intense worry.

“It’s such a personal matter for Bruce and the band that I don’t think now is the time to talk about it,” Harris said. “It’s Bruce’s story to tell when he feels the time is right. The one thing I can say is that Bruce is a trooper and more than ready for the next chapter of Iron Maiden. What matters now is that we’ve got an album coming out that I think our fans are going to love and we’re all excited to share with them.”

Still, it's been difficult to move past something that would have shattered Iron Maiden. A tour in support of The Book of Souls, Harris added, has quickly gathered new importance, since it's never been more clear that Iron Maiden should view “every show as sacred.”

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