The little oases within the rotten commercial-radio system, a system in which programmers rely on national charts and consultants to dictate their playlists, are the heavenly mix shows that arrive almost nightly on The Beat (100.3 FM) (whose new competitor, Q95, just debuted its own mix shows). Real live human beings with real live taste and creative energy mix beats, toss on obscurities and unbroken gems, and create an airwave party that harks back to the days of freeform R&B radio at its best, where a DJ can save your life and turn a dumb grocery-store errand into a goddamn party. The two best right now are both on The Beat, and, depending on your mood, either could win: DJ Kaos' Friday-night throwdown, from 7-10 p.m., and DJ Needles' Saturday jam in the same slot. Needles drops the best of the independent and classic, whereas Kaos' fare is more pop- and party-oriented. Either will do, though for sheer fun fun fun, we're gonna go with Kaos' show; it's a hoot and will give you a taste of the joy of the best in contemporary hip-hop, a music that's blossoming before our very ears.