The Mix-Up is the Beasties' first all-instrumental record, grounded in soul-jazz, a sound they've been mining since Check Your Head (arguably, even Paul's Boutique had elements of the sound in its samples), as they peppered their albums and B-sides with lazy, hazy funk jams. Most of these were gathered up on the 1996 compilation The In Sound from Way Out, which undoubtedly sounds similar to The Mix Up, but that's at heart an odds-n-sods collection, bearing the evidence that it was patched together from different sources. The Mix Up was designed as a specific project, so it holds together better, and it's also decidedly less knowing in its references than the cleverly kitschy In Sound. This is a fusion of sounds - cool organs, elastic guitars, loping basslines, rolling rhythms - where all of the elements are integrated together, turning into a style that's recognizable as uniquely, undeniably the Beastie Boys, even if they don't utter a word on this record. As always, they're more about feel than instrumental acumen, but they've sharpened as players, creating tighter, assured grooves and seamlessly blending their fascinations with funk, dub, soul, and Latin rhythms.