It all comes down to Stevie Nicks. She's the one person keeping Fleetwood Mac from completing their first album since 2003's Say You Will, the band's co-founder, drummer Mick Fleetwood, says.

He told Rolling Stone Fleetwood Mac have completed "a huge amount of recorded music," but "none of it's with Stevie. Or very little. Some of it is very, very old stuff that Lindsey [Buckingham] maybe did with her years and years ago. We're not quite sure what will happen with it."

Fleetwood similarly blamed Nicks for a long-delayed Fleetwood Mac tour that was supposed to start in 2012, crediting an "obsession" with her solo career. Apparently, not much has changed. "She just doesn't want to spend the time right now," Fleetwood said. "And we're quietly saddened about that, but also I sort of understand."

The ironic part is that Christine McVie's belated return to the band led to a huge influx of new material. "I do know that when Christine came back, she came back with a bag full of goods," Fleetwood added. "She f---ing wrote up a storm. She and Lindsey could probably have a mighty strong duet album if they want. In truth, I hope it will come to more than that. ... There really are dozens of songs. And they're really good. And so you think, "S---, I don't want it to be that, decades later, when we're all pushing up daisies, someone hears this stuff and goes, 'Well, that should have come out!'" So we'll see."

Whatever happens with Fleetwood Mac's studio work, plans are moving forward for another tour, according to Fleetwood. "We're all dedicated to getting together about a year or so from now and going and doing another two years of touring all over the world, probably," he said.

Fleetwood Mac Albums Ranked Worst to Best

More From Ultimate Classic Rock