For those keeping score at home, the latest lineup of this endlessly regenerative California-rock legend goes Lindsey Buckingham, Stevie Nicks, Mick Fleetwood and John, but not Christine McVie. It’s the first Mac album in sixteen years for which Buckingham has written songs; tracks such as “Peacekeeper” and “Steal Your Heart Away” prove that Mac’s singular vibe — a sunny, countrified lope against which urgent breakup lyrics blaze — has always been his doing. Say You Will also proves that this is the only band that knows how to play his songs. The album is a randomly sequenced display of Fleetwood Mac’s best instincts: Buckingham’s bittersweet tunes about playing for keeps; Nicks’ tough, swirly songs about fragile and wicked women; and the experiments the group can’t stop indulging in (near-classical and metal-inclined guitar, teen pop, an incoherent number about the media). And when this accumulation of chops rallies for a single, the result is the perfectly mellow breeze of the title song. Not that this is a band that needs to be relevant — in California, no one has to grow old.