In one fell swoop that came in the form of a surprise, free-of-charge digital release a week ago Monday, Greg Gillis overturned the idea he'd been instrumental in creating at the birth of mash-up culture. To wit: the transience and faddishness of internet-fueled, DIY laptop music and the speed at which it renders artists irrelevant. Now that we've got All Day, another ultra-sample-dense, hyperactive party soundtrack that's impeccably loyal to his brand, it's almost as if Gillis's two-year hiatus had never happened. Sublime production quality and danceability aside, this mix scores as a chronicle of American pop music that elicits a dual layer of nostalgia: the first for the sampled songs themselves, the second for the thrill of the novelty of early mash-ups. Gillis, more than ever, is a meticulous micro-historian, reconciling the past two years of airwaves with those of preceding eras (vocals from Ludacris's "Move, Bitch" straddle Black Sabbath's "War Pigs" and Jay-Z's "New York State of Mind"; Waka Flocka Flame barks over Mr. Oizo's French-house "Flat Beat") and allowing listeners to experience the blissful mindfuck of trying to map out the pieces of an updated, upgraded puzzle.