It goes without saying that Fleetwood Mac fans have been more than a little excited about the official reformation of the classic lineup.

As it happens, the band is, too. So much so that Lindsey Buckingham and Christine McVie, agreed to talk about collaborating ahead of the band's upcoming tour.

"We've been working very closely together, so there is a freshness," Buckingham said.

Buckingham tells Billboard.com the group has been working -- without Stevie Nicks -- in a Los Angeles studio.  He says they're "very far along" on eight tracks that originated with McVie, and have at least a half-dozen others in the works.

He adds that the songs developed "really organically in a way that seemed appropriate," and they're "all very excited about it."  Christine says the new material is diverse, ranging from "sort of blues-based songs to very commercial songs," and sounds "really fresh."

McVie adds that fans shouldn't expect a new album before the group's fall tour, and anticipates the disc will arrive in 2015.  However, Buckingham says the timetable is fluid.  He explains that they don't want to release anything before it's ready, but they're "very proud" of their new work and want the fans to know about it.  He says the amount of "clamor" there is over the project could influence how quickly it comes out.

Fleetwood Mac – with Christine – will launch its tour in Minneapolis on Sept. 30.

1987's "Seven Wonders" which found new life with Nicks' appearance on "American Horror Story: Coven"