To celebrate their 20th anniversary -- marked from the release of Ten, not their formation -- Pearl Jam launched a multimedia project called Pearl Jam Twenty, spearheaded by a Cameron Crowe-directed documentary to which this double-disc set provides the nominal soundtrack, both supplemented by a memorabilia-laden coffeetable book. It's a project not dissimilar to The Beatles Anthology and, appropriately enough, the PJ20 soundtrack is a weird hodgepodge of demos, alternate tracks, outtakes, and live cuts all culled together under a title that suggests it has broader appeal than it does. This is yet another release designed for the dedicated, the kind of fan eager to dissect and analyze, the kind who won't mind a few wordless demos in a row. Which isn't to say that the music here is without merit: unearthing a Temple of the Dog demo with Chris Cornell on vocals is an interesting curio, hearing the group create a bridge back to its roots by covering Mother Love Bone's "Crown of Thorns" on a tenth anniversary gig carries some poignancy, there's an appealingly ragged duet with Neil Young on "Walk with Me," and it's certainly interesting to hear demos by Matt Cameron or Jeff Ament, particularly when the latter's "Nothing as It Seems" is sequenced next to a full-blown live version from a couple of years later. Still, these are particular pleasures, pleasures that won't be apparent to those fans who gave up around Vs. or Vitalogy, listeners who may be tempted to give this a whirl based on the documentary. But the soundtrack to PJ20 is not for them, it's for those who have stuck with the group through thick and thin, through any number of new drummers, and they'll certainly find much that rewards their fandom here.