If it was Tuesday, it must have been P Street. You could tell for sure by the markedly unglamorous sidewalk, bounded by the plant store on the east and the Gulf station on the west, chock-full of meandering painters and sculptors. They were there, hundreds strong, for the Washington weeknight ritual called:

The Art Opening.

Or more accurately, the Art Openings. Sometimes three, often five, and almost always packed into a single, traditional Tuesday night of Gallo Hearty Burgundy and plastic cups. Heavily accented, on many occasions, by waiters who sculpt on the side, sculptors who wait on the side, a dealer like Harry Lunn who has thousands to spend, a suburban dentist who has less. And the hangers-on, marked by mauve eyelids, who think it's the neatest night of the week.

The successful openings have the look of bustling sheep pens because galleries, as is their nature, are small establishments. Much too small, usually, to handle the faithful and predictable faces who turn up week after week. If they're luckey, they can eat free. If they're really lucky, they can find out who's living with Fred. If they hit the jackpot, they can meet an interested collector whose rich uncle just died.

"I think it's all very funny," says one local artist who acted as our Tuesday tour guide. "People skittering around here and there. A sense of humor gets you through."

Some art parties are the stuff of legend. Washington 1972 was a good year. Or a bad year, actually, for then-Corcoran director Gene Baro, who was punched soundly in the face by his boss during one of those sparkly, black-tie affairs. (The squabble, as the accounts go, was over who would pose for pictures with a certain artist.)

"He bled like a stuck pig," rembembers dealers Lunn, who watched from the sidelines.

Now bear in mind, that was a glittery opening. The Tuesday gallery openings are generally not for the David Lloyd Kreeger and Livingston Biddle crowd, although Joan Mondale did make a P Street appearance last fall. (They talked about it, these middle-level working artists, for weeks.)

So generally speaking, Tuesday night art parties are brawl-free, even safe. And not only that. To the struggling young artist or struggling mid-level artist, they're practically essential. Certainly helpful, most say, to the career and the social life. Good gossip territory, too. And God forbid you should look at the walls.

"Art openings," a Washington painter says simply, "arnen't about art."

Come, then on a whirlwind Tuesday tour of six galleries in two short hours. Our guide is Jane Dow, a 34-year-old moderately struggling painter who once thought the Tuesday circuit meant "heavy art talk." Now she knows better.

"It's a good way to meet contacts," she says. "It's a word here or a word there that builds a reputation. People like to know the person, to see the flesh."

Thus, a Tuesday tour (which also occurs, through less frequently, on other nights and afternoons) becomes a parade of artists, a promenade from gallery to gallery. A preciesely executed waltz, if you will, along two city blocks of P Street.

But before the tour, a quick prologue to get the essential elements:

Art dealers, for sure. The successful ones, with money to back careers, are very powerful.

Gossip, certainly. And on this Tuesday, Jan. 8, it's mostly about the alternative "Laundry" show as reaction to the Corcoran realist exhibition opening later this month. Some of the realists, artists complain, aren't really realists. But that kind of talk gets technical. More innocuous gossip comes out as "So what are you working on now?"

Self-promotion. Naturally. Usually in the form of "I've got a show opening on the 5th. Are you on my mailing list?"

The sense of bar mitzvah. Or coming-out party. "You're showing two years of your life's work," says Dow. "It's like publishing a novel." And from Jean-pierre de Andino of the Osuna Gallery: "When an artist has an opening he's sort of baring himself nacked to the world. It can be a very traumatic event."

Energetic socializing. Also included here is energetic wine or champagne sipping. "The struggling young artist and the struggling young artist's friends have a tendency to drink to make up for all the drinks they're missed during the week," observes Lunn.

There's energetic singles cruising too. "But it's not so sleazo, because people have a reason for being there," says artist Manon Cleary."At a singles bar, you're likely to meet a plumber. At least at an art opening, if you meet a plumber, he's probably a sculptor on the side."

The hangers-on. Or those who would love to be artists. Wouldn't most of us?" says Stan Weintraub a red-haired man who edits magazine articles with titles lke "The Instability Boundry and Growth Rate Contours of the Gyrotron Amplifier" (and that isn't even all of it) for a living.

He has made one clay bowl would rather be an abstract painter, and is a nearly guaranteed fixture at any art party. Some even say that if he doesn't show, your opening s a failure.

But enough. It's 6 p.m. and we're off. Supper in SoHo

First stop is the Diane Brown Gallery. 2028 P St. With Dow is Ed Cutler, bearded friend. Because it's early and because there are a few tweedy souls who look as if they might even buy at the art. But not for long.

"Great neighborhood. It's so cheap, you can't believe it. I mean, you c can eat for nothing up there."

This conversation, as you may suspect, is not about the proto-cubism of Paul Cezanne as his response to the shibboleths of neoclassicism. Rather, it's about one reason local artist Bill Lombardo wants to move his studio from Washington to New York's SoHo. As you heard, cheap eats. In Little Italy, especially.

Dow agrees appreciatively, at the same time congratulating him on his show and reminding him that she has one of her own in February. As dealer Chris Middendorf has explained: "If you're an artist, and you appear at somebody's opening, then that person is apt to show up at yours."

In the middle of the airy, plant-filled room is Diane Brown. That's Diane Brown, dealer. "God, Diane," says Dow, "you're so gorgeous." Like long-lost college roommates, the two hug. "All of us," Dow has said earlier, "are being nice to each other for business reasons. But we're also being nice to each other because we like each other."

Well, whatever. It's time to move on. Canvas and Cheer

Second stop is the Foundry Gallery, 2121 P. Before she enters, Dow politely places her empty champagne glass from Diane Brown's outside the door.

Inside, there probably wouldn't have been room for it anyway. There certainly isn't room for looking at the show, entitled "25 Washington Artists: Realm and Representative." Yes, this is definitely a cheek-to-cheek scene.

"You look wonderful," says a friend who seems to pop from behind and oil of a pregnant woman. "Your hair is long."

"I'm getting fat," responds Dow.

Actually, she's not. At least it doesn't look like it from the navy wool slacks, turtleneck sweater and blazer she wears, and outfit that with the barrettes in her hair makes her look more like an English major than a painter who will stare for months at a canvas.

She sees another friend. "Are you okay?" asks Dow." Are you depressed or anything?" No, matter of fact, she isn't.

Anyway, it's hot. And the serious buyers have come before the opening, or will show up later, when it's less crowed. Let's get out of here. three for the Show

Next door is the Osuna Gallery and party No.3. And a Manon Clearly, one of three artists who's showing here. She has had more placid evenings.

"They delivered this show 15 minutes after it opened," says Cleary, who is thin, smokes her cigarettes down to the filter and wears red boots.

"How are you?" asks Dow.

"Drunk," replies Clearly.

"How's Michael?" asks Ed Cutler.

"He's into building houses," says clearly.

No, you won't find talk of Cezanne and neoclassicism here, either. Time is running short, so Dow heads for the door. On the way, she is stopped by a young man and woman.

"We're the couple that paint together," the woman says. "Tell me about you. Oh I thought your name was familiar. Where's your next show? Oh, I'll give you my card so I'll be sure to be on your mailing list."

Outside, on the way to gallery No. 4, Dow throws the cards away. Trials and Trauma

Here are two minks and one big, black bear coat. A more established crowd for an established Gene Davis, who says he would avoid his own openings if he could. "I tolerate them all right," he sighs.

Tonight he has a friend in Nacy McIntosh, an owner of this gallery, Protetch-McIntosh. "A necessary evil," she calls opeinings. "To me, they're a very unpleasant experience."

And confusing sometimes. At another of his openings, Davis remembers, a woman walked in to see his micro paintings and cried for all to hear, "Where's the art?" Val Lewton, the assistant chief of design at the Corcoran, remembers another Davis micro painting opening where a small child carried one of the works home in his pocket.

"It was his size, right?" Lewton says. "So he just took it." His mother, horrified, made him bring it back.

Dow doesn't stay long at this opening, mostly because she's worried about making it to the others in time. She does, however, say to Flo, Davis' wife, "Do you think that you all could come to my show?" Hard and Dry

Now there's a cab to catch for Columbia Road. But before that, Ed Cutler wants to make one more stop on P Street, this one at the Jane Haslem Gallery. Dow doesn't.

"Oh, come on," says Cutler. "I mean, it's the only gallery that's serving hard liquor. We need substance." Well, all right. They head up the sidewalk and look, there's Jean Maire.

"Jean Marie," Dow calls to this woman in lots of fur. "Listen, you're going to have to come see my stuff."

"We'll have to get together," agrees Jean Marie, who is Jean Maire Antone, the owner of an Annapolis gallery that has shown Dow's work during the slow summer months. "Call me. Or I'll call you. For sure."

Afterward, Dow remarks: "I hadn't gotten around to calling her in six months. I was hoping to see her at the openings."

But back to gallery No.5."Now, we're really only going to stay for 10 minutes," Dow says with a nod in Cutler's direction. "I'm just doing this to humor him." As it turns out, Cutler doesn't need much humoring because the bar is closed. So they get a cab. Last Look

So. Here is gallery No.6, the new Middendorf/Lane that's just moved to Columbia Road but is still a psychological part of P Street. Outside on the street, a young woman in long, dark hair and boots offers Cutler a sip of her champagne.

"Asti Spumanti," he guesses. And no, he doesn't know her. "I swear to God I don't know her," he insists. "This sounds like my ex-wife."

Inside, where Joe White's paintings room. Dow heads for Roddy Frantz lead singer for Washington's new wave group the Urban Verbs Upstairs is Robin Rose, another Verb and artist. He's helped tie the new wave crowd and d.c. space crowd into this working artist crowd.

"Music and the arts have always over-lapped," he says. "Like jazz influenced painting in the '50s. I've been doing both since high school."

"It's Dow's turn at the bathroom."I'm tired," she says.

But there's still a dinner party of chicken tetrazzini at Mary Swift's, the collector and patron who lives in a huge Georgetown house. It should go on until well past midnight.

The evening, Dow decides, has been astoundingly busy. Earlier, she had tried to figure out what makes her -- and the others -- participate in the P Street waltz.

"Everybody's nervous," she had said. In the art world, there are no absolutes. It's built on what people think and not on actual fact. If someone thinks someone is an important person, than they are.

"It's an interesting phenomenon. It must be necessary," she added with a twist of logic, "or else we all wouldn't keep going."