When critics examine the infrastructure of a city's musical "scene," they usually focus on clubs, recording studios, even radio stations. Too often record stores -- the places where folks actually get their hands on a physical slice of all that musical activity -- are ignored. Blue Note Records, however, has never flown under the radar. It has had a lock on this category for eons. Regardless of the offbeat sounds lauded by New Timesscribes -- far-out Chicago jazz, underground NYC rock, Bay Area hip-hop, Nigerian Afro-beat, Cuban son, even Miami bass -- you could usually find it amid Blue Note's bulging stacks. And thanks to the knowledgeable staff, chances are you'd also end up leaving with a lot more than you originally set out for: Jon Spencer Blues Explosion fans might be gently led over to a vintage Robert Nighthawk album; D'Angelo devotees might get hep to Bobby Womack. And in a city known for its Balkanization and short historical attention span, that's no small feat. Long-time shoppers therefore were a bit alarmed to see this winning formula tinkered with recently: An economic crunch forced Blue Note's entire jazz section -- once honored with its own (apparently now too expensive to rent) room -- to be carted off to a separate annex. It's nearby but definitely not receiving the stocking attention it once did. Moreover the days of one-stop shopping, not to mention aesthetic cross- pollination ("Hey, if you dig that Tortoise record, how 'bout a little Sun Ra?"), are no more. Fortunately the rest of Blue Note remains unchanged, as do the odds that somethingfunky is going to be playing on the stereo when you step through the front door. Here's hoping it stays that way.