IMAGINE: IT'S a slow Thursday night at your favorite neighborhood bar -- a worn but well-tended joint where they always know your name and sometimes cash your checks. You're just about done with the $1.10 draft that went with the chili platter; it's almost time to pull out the standard five-dollar bill, from which you will get back enough change to leave a reasonable, if not particularly memorable, tip.

At this point, Bonnie Raitt appears from somewhere in the back, carrying a guitar.

She smiles at you and the other 23 people scattered around the room, strolls up to a bar stool under a small spotlight, and proceeds to sing your heart out for the next two hours. During this time, you have two more drafts (still $1.10 each), 17 attacks of wildly sincere applause and the thrill of your life when Raitt comes by your table after the show to thank you for coming and to autograph your napkin.

Sound familiar?

No, of course not. I made it up. Had to.

This is 1984. This is Washington. And maybe Stevie Wonder actually did drop by The Saloon in Georgetown one night this spring to sit in with a local jazz quartet, but that was a fluke. A happy fluke, but a fluke.

We, on the other hand, are talking day-to-day, nightclub-to- nightclub reality.

And in reality, if you've been in a Washington nightclub anytime lately to see a performance by some nationally known act -- be it Sarah Vaughan, Southside Johnny or Sun Ra -- you most likely were at the Bayou, the 9:30 Club or the soon-to-be- history Wax Museum (for rock, pop, blues); or at Charlie's or Blues Alley (for jazz); or at the Birchmere (for bluegrass, folk or something else acoustic); or at Kilimanjaro's Heritage Hall (for African, reggae, Latin, soul or rhythm and blues). And in reality, you probably paid anywhere from $5 to $25 to get in -- and once there, the beer didn't cost anything like $1.10.

Maybe you had the time of your life, like most of the thousand people who two months ago did, in reality, catch Bonnie Raitt last time she was in Washington -- each of them paying the Wax Museum, in reality, $15 for the seat and $3 per drink. Such time-of-your-life judgments are generally based on your expectations -- of the performer, mostly. But also of the room.

Well, we're not going to talk so much about the acts themselves -- Washington is pretty much on the same tour circuits as New York, Boston, Philadelphia, Baltimore, and is generally a better club market for jazz than rock, or for bluegrass and blues than new (formerly new-wave) music. We're going to talk about what you can expect -- from this town's most ambitious, best-known listening rooms -- when you leave the safety of your own home for the would-be serendipity of theirs. The Big Clubs, in other words -- seven whose floor plans may or may not be officially Big, but whose plans, officially and consistently, are.

And before we take you to the specifics -- meaning the seven aforementioned clubs (including the Wax Museum, which, though scheduled to close November 4 after two valiant and uneven years, does stand a chance of resurrection) -- let's run quickly through four general expectations. FOUR GENERAL EXPECTATIONS

Fun. Expect to have it, sometimes despite everything. But use common sense: Avoid arriving in Georgetown in a 20-foot Winnebago on a Saturday night, for instance. Refrain, as a rule, from call brands at Blues Alley, unless the company's paying. And if your date is not the kind of woman you can envision having the back of her hand stamped with an indication of her age, stay away from the 9:30 Club. Otherwise, no problem. You will have fun. First, however, you will have to have:

Money. Most times, a night with Mel Torme at Charlie's or Todd Rundgren at the Bayou is going to cost you more than a night at home with a pizza and a VHS dub of "Animal House." Most clubs in town pay the act with what they get at the door; what they sell you once you're there -- $3.50 Heinekens, $1 baskets of chips, frozen-fruit cocktails for $4.95 -- makes for what the clubs call profit. As a rule, expect to spend at least as much at the club as you spent to get in -- and more if you have dinner. Which brings us to:

Food. Six of these clubs operate on an open-seating basis (at the 9:30 Club, which has minimal food and no seats in the main room, it's more like "open-standing"). Thus, if you go early to eat before the show, you'll get two things: a good, possibly great, seat -- and a tab that may require a quick sprint to the nearest MOST machine, or the use of plastic money. (Including drinks, food, tip and cover for two people, we're talking anywhere from $30 to $50 at the Birchmere or Bayou to $100 or more at Charlie's or Blues Alley. And this doesn't include parking -- which, at all but the Birchmere and maybe the 9:30, will cost you either more money or a minor headache.)

Keep in mind that at some clubs -- Blues Alley, for instance -- the food is usually worth the higher price; in others, it is usually worth the lower price (and here the Birchmere comes to mind). Because of the aforementioned In-House Consumption Profit Rule, though, all of the clubs would like you to come early, even if you're not planning to eat there. Which brings us to:

Showtimes. In general, expect to see the act you came to see significantly later than you thought you'd see it -- anywhere from a half hour to as much as two hours later, if there's an opening act. Some clubs are better about this than others (but the Bayou is not one of them). However: If the main draw is even moderately popular, knowing what the Actual Showtime is isn't going to get you anywhere, because you still have to show up early enough to get a seat in the same city block as the stage.

Anyway, speaking of showtime:

The following guide is geared toward the kind of hopeful, pragmatic souls who'd very much like Bonnie Raitt to play their corner saloon but know better than to wait around for her to show up. Especially on a Thursday. It is also meant for those whose biggest reason for staying home is not the budget, the babysitter or something better on HBO (hah!), but most times merely that old Fear of the Unknown.

Herewith, then: Seven Things That Go Bump (Bump, Shh- Bump) in the Night. Or something like that. BLUEGRASS: ONE FOR THE SHOW

The Birchmere: Like the bluegrass, folk and country-pop shows within this 300-seat Alexandria hall most Wednesdays through Saturdays, the Birchmere itself wears well. If its seven years of shopping-center storefront operation have thus far escaped you, probably the best night to sample the place is Thursday -- most any Thursday, when the Seldom Scene takes the stage in front of what feels, and responds, like one big happy family. The cover these nights is $7, and that's more or less a median. The other nights are taken up largely by bluegrass acts known (such as bluegrass is known) throughout the land, for admission prices of $4 to $8.50, with regular forays into the $10 to $12 range for better-known country and folk artists like Pure Prairie League, or Mary Travers (next Friday).

Food at the Birchmere is highly optional -- burgers and various fried things, nothing to particularly sing about -- and beer, which isn't optional (there ain't anything else but soda pop) and costs $2 by the bottle, $7 by the pitcher. For the most part, it's the music that defines atmosphere here; decoratively inert paneling covers most walls, red-checked tablecloths most tables and worn carpeting most of the floor. The guy behind the sound board in back is usually the owner, Gary Oelze. There's a record store downstairs, and a big parking lot next door.

Don't get the zucchini sticks. JAZZ: TWO FOR THE MONEY

Blues Aley: When things go well in front of the plain, esthetically correct brick wall behind the stage of this 20-year-old, 175-seat club, they go extremely well -- and you will remember the night more, say, for the electric charges of guitarist Pat Metheny or the eclectic trumpet of Wynton Marsalis than for the $89 bill, including tip, for two creole-style seafood entrees, drinks and the cover. (Covers range here from $8 to $15. Usually $15 if it's somebody you really want to see.)

Entered through a nondescript door off a nondescript alley in otherwise descript lower Georgetown, the club is low on airs and at least as high on intimacy as on drink prices. This is an uptown jazz club, for sure, but whenever possible get down here for the late shows on any Friday or Saturday, when things are often considerably looser -- both in terms of leg room and performer-to-audience rapport.

The best seats are had by those who show up as parties of four and want dinner first, thus being seated directly in front of the stge, and by the parties of anything who sit at the bar in back. The least hassled-looking customers are usually those who parked in the waterfront lot at the foot of Wisconsin Avenue, about a block south ($3; also smart for Charlie's and the Bayou).

Blues Alley, which last month opened for live-jazz lunches, is also expanding its bookings to non-jazz artists -- Jesse Winchester in August, Phoebe Snow this weekend, to name a couple. Booking manager Jeff Lettes says you can expect more of this.

Charlie's booking consultant Michael Jaworek promises a similar move toward a broader audience at the Georgetown namesake of jazz guitarist Charlie Byrd -- that is, more pop acts, some folk, maybe even some big-name comedy, all sometime this winter and most still unconfirmed. For now, though, Charlie's remains pretty much what it's been since its opening in 1980: an elegantly sterile, 170-seat restaurant that also happens to have live, high-quality jazz. And which happens to have one of the highest rents of any live-music club in town.

Charlie's jazz/cabaret musical fare is frequently unmatched -- this being the place in town to see a Bobby Short, a George Shearing, a Sarah Vaughan, or a co-founder named Byrd himself -- but the current unmatched prices ($25 per person for Short, plus a two-drink minimum) have cut badly enough into business that manager Michael Finacchiaro, brought in this summer to run the place, is deeply immersed these days in what he calls a "concept renovation" to cope with the dwindling base of the kind of 35-ados who can afford to drop by regularly.

Jaworek's broader-appeal bookings are a big part of this, but so are the "more wholesome" prices Finacchiaro says Charlie's intends to institute sometime this winter: probably $35 a seat for a combined show-dinner package, or $25 for two drinks and the show. This may compensate for the show room's weird layout and to-small, too-high stage -- but then, Finacchiaro says this will all be renovated within the year, too. Meantime, you could try the more relaxed (i.e. no cover) and suitably noisier Riverfront Piano Room -- which is now called the Riverfront Cafe, where Bob Diener still pilots the piano most nights. ROCK: THREE, GETTING READY TO BE TWO

The Wax Museum: Colonial Parking, a subsidiary of which owns this two-year-old rock, pop, jazz and whatever emporium in near Southwest, is closing the Wax in two weeks, due primarily to a marked lack of profit. Several concerns are said to be interested in operating the facility -- possibly because it has the most sophisticated sound and video system around, plus more seats than any other club in town -- roughly 1,000, about half of them excellent. At least one potential concern, however -- Dave Williams and his Cellar Door Productions, owners of the Bayou -- is not interested. This is partly because of what Williams calls the Wax's off-the-beaten-path location. And partly because Williams is planning to build a new 750-seat club somewhere in the West End, God and the D.C. drinking-age laws willing.

The Bayou devotes weeknights to most of its national bookings (good-time rock, heavy metal, power pop, R&B, rockabilly), largely because it has no trouble filling up on weekends with college-age devotees of the mostly powerful and local bands who frequently play here Fridays and Saturdays. If you normally fill one of the Bayou's 500 seats on weekends, I don't have to tell you what a great, terrific place this is. (Chances are if I did, I'd have to shout for you to hear me, anyway.)

But the Bayou has another constituency -- the ones who show up occasionally at midweek for specific big names; the ones, say, who like Howard Jones enough to buy his music but not his wardrobe (especially not for the office). Or who come to see one of Southside Johnny's six dozen annual shows here (every one worth it, though, really). And this constituency has to believe the Bayou isn't exactly great or terrific, but just kind of okay.

Why? Maybe it's that one note -- sour -- played continuously by the cowboy checking IDs at the door. Or maybe it's the two-hour wait between the time you get in -- too late for a good seat, but there are only about 100 of those to begin with -- and the time they roll up the video screen and roll out the talent.

Or maybe it was just that you should've found another way to kill that time besides killing $2.90 Heinekens. Or $5.75 pizzas.

Particularly the pizzas, come to think of it.

9:30 Club: Like the Bayou, the 9:30 also tends to book its out-of-town draws during the week, but the resemblance stops here. It takes only 250 or so 18- flat black interior of Washington's foremost, and scrappiest, new- music club (what the ladies on the N2 bus call the "punk" scene), and this means that booking manager Seth Hurwitz is freer than most of his peers to bring in . . . well, different stuff. Modern English. Cyndi Lauper. REM. The Bangles. Jaluka. The Violent Femmes. T-Bone Burnett. If it's a weekend night, you'll generally find some of the more original local bands on stage here -- the Slickee Boys, 10,000 Maniacs, Barrence Whitfield, Tommy Keene, the Raybeats, the dbs. You know.

But don't take my word for it. Walk around the corner from Ford's Theater one night after the curtain closes on some patriotic fare or other, and turn right at 930 F St. After the guy in the long hallway stamps your hand (covers range from $3 for a three-band local show to $8 to $10 for the big out-of-towners), and after you make it past his hairdo, you'll find yourself in a large, generally throbbing room -- standing-room only, because there ain't no chairs. There'll be a bar to your left, the stage ahead and and a video-booth loft on the right. If you keep making lefts, you may find a seat in the somewhat quieter back bar, where ordering a $2 beer is possible without having to take voice-altering drug of any kind. At this point, feel free to stare at the woman in the black-leather jumpsuit and spiked heels, but don't let her hear you say anything bad about the band. She's with them. REGGAE, AFRICAN, CALYPSO, SOUL: FOUR IN ONE

Kilimanjaro's Heritage Hall: Speaking of different. The cover charges at this nonchalant Adams Morgan nightclub are comparable to elsewhere ($8 to $14), but what's on stage most nights is not. For the last nine months, booking manager Seedy Lette has been filling the Kilimanjaro restaurant's adjacent 500-seat, piecemeal-with-dignity Heritage Hall (formerly the quarters of an auto-repair shop) with live music close to his heart, if not his Gambian heritage. Every Saturday is "International Night," which means African and calypso; Fridays are reggae nights; and in recent months, Lette has set aside Wednesdays and Thursdays for soul and R&B acts: Wilson Pickett, Harold Melvin and the Blue Notes, Phyllis Hyman, the Manhattans and others.

What distinguishes Heritage Hall, besides its international bent and African menu (a plate of roasted goat meat: $6), is its high back-and-forth quotient -- table-to-table, but especially performer-to-audience. You would have noticed this last Saturday, when Lette brought in Brazilian pop star Gilberto Gil to a packed, primarily rapt house. You might notice it next weekend, for two shows by Nigerian Sunny Okusuns and the Ozzidi Band; Lette is sure you'll notice the following weekend, for three consecutive nights of Zaire's Franco and T.P.O.K. Jazz.

You may also notice that nobody in Heritage Hall asks anyone to leave after the show's over, generally at about 11:30, or that the performers can sometimes be seen mingling -- yes, with the audience -- afterwards, while a deejay spins related recordings. Or that dancing, in the back as well as right in front of the stage, is actually encouraged during most live shows.

Unless you see this happen in person, however, you should never believe such hysterical reports. I mean, someone even said a bottle of imported beer costs $2.50 at Heritage Hall.

THE BAYOU -- Wisconsin and K NW. 333-2897.

THE BIRCHMERE -- 3901 Mt. Vernon Avenue, Alexandria. 549-5919.

BLUES ALLEY -- 1073 Wisconsin Avenue NW. 337-4141

CHARLIE'S -- 3223 K Street NW. 298-5985.

KILIMANJARO'S HERITAGE HALL -- 1724 California Street NW. 328- 3838.

9:30 CLUB -- 930 F Street NW. 638-2008.

WAX MUSEUM -- Fourth and E streets SW. USA-0000.