Christine McVie officially returned to Fleetwood Mac back in January.  But, she's going to much more than go on tour and play the band's classics.

Fleetwood Mac is working on a new album.

Lindsey Buckingham offers an update to Billboard.  Buckingham says, "We got in the studio not knowing what to expect, and the chemistry was just unbelievable... We got eight tracks very far along, like, 75 percent done. It just played out really organically in a way that seemed appropriate."

Buckingham adds that the band has "14 or 15 things, and some other things we want to get to down the line...Knowing me, I'm going to be pushing for a double album."

Fleetwood Mac will kick off all fall tour on September 30 in Minneapolis.  They will play Verizon Center in Washington D.C. on Halloween night.  Buckingham says their new music will not likely be ready prior to the tour.