The laid-back exclusivity of Nublu -- a Lower East Side lounge claiming Wax Poetic as an ever-morphing house band -- has proven to be a productive environment for the future of what was once called "acid jazz" and is now called "downtempo." In the cozy surroundings of Nublu, musicians, singers and progressive-minded beat junkies convene to create music that's luxurious and challenging. With guests and regulars on equal footing, the vibe is constantly changing. Whether the mike is held by Norah Jones (a member of Wax Poetic for a year), U-Roy, Saul Williams, 'Dea Davenport or less-known talents like Nil Karaibrahimgil, the band responds accordingly with music that's as organic and sultry as it is tech-conscious. It's the height of cosmopolitan chic, and that's just fine.