The most interesting narrative of Fleetwood Mac -- one every music writer hopes to chronicle and every fan dreams about when reading between the lines of "Rumours" -- involves romance and adultery. The stories behind lyrics of heartbreak and betrayal and love and acceptance are well-documented, but in recent interviews with Lindsey Buckingham and Christine McVie, the bandmates assert that the past is just that. Fleetwood Mac released its best-selling album "Rumours" 40 years ago; Christine McVie left the band 16 years ago.