Nostalgia numbers are the here-and-now. In other words, you could play Kon and Amir’s The Cleaning at any party and have everyone feeling the groove. Of course, you’d need to put up with a few knuckleheads asking how-or by what reverse time-travel scheme-’70s musicians like James Mason managed to filch samples from De La Soul and render them as full-fledged funk joints (“Sweet Power”). The Cleaning is a product of many long hours spent painstakingly dissecting breaks, combing through record collections, and matching two-second soundbites with their original tunes-and that’s why Kon and Amir should get their propers.