Since the Beastie Boys released License to Ill more than two decades ago, all paths into New York nostalgia and downtown have led back to them. So what's a guy named Adrock, or MCA, or Mike D to do? No wonder, with The Mix-Up, they've got nothing to say. It's an all-instrumental record (a career first for them), and by all aural indications, a desperate move. If 2004's To the 5 Boroughs was an exercise in reminiscence masquerading as a nod to current events the erstwhile New Yorkers emerging post-September 11 to hail the city they knew when they were young The Mix-Up is a kind of admission of obsolescence. Not that it's bad tossed-off, underdone, monotonous, unfinished, and redundant maybe, but not bad. Think "Lighten Up" or "Groove Holmes," the lounge-y instrumental tracks that laced Check Your Head,minus the dub and the samples, but leaving in the low-key vamps, Fender Rhodes organ, crispy 4/4 snares, congas, vintage distortion, and a metered shuffle. "Off the Grid" crams in handclaps, a meandering guitar solo, and an ethereal keyboard line. Mostly it stands out because it doesn't repeat anything incessantly. Looking to old interludes for new inspiration makes brutal, inevitable sense, given that the Beastie Boys made an art of plundering virtually everything they could get their hands on, raiding their own past. What's available to them but the history they once made?