David Yassky, a 28-year-old congressional staffer, didn't want to spend $125 for an official inaugural ball ticket. So Yassky and a group of similarly strapped but party-ready friends organized their own ball.

Thus the New Generation Inaugural Ball, with its $30-per-person tab and "black-tie encouraged" fashion advice, is planned for Jan. 20 at the Kennedy-Warren Ballroom. It is one of a number of untraditional events appearing on an inaugural week agenda that is at last becoming clear.

"We want to do something that we all could celebrate as a group," says Yassky. "There are enough of us excited about politics and enthusiastically Democrat that we knew we could have an event."

More than a few people have had the same idea, and the result is a week that is shaping up to be a social landslide that will feature the most extensive and varied number of events on an inaugural calendar in recent memory. As the Presidential Inaugural Committee this week finalizes its official list of events, large-scale celebrations are also being planned by myriad special interests, including People for the Ethical Treatment of Animals, the Screen Directors Guild, MTV, the Gay and Lesbian Victory Fund and George Washington University.

The final count will include at least 19 full-fledged balls, 11 of which will be produced by the presidential committee. To accommodate the clamor for official events, the committee is expected this week to announce an additional ball at the Old Post Office Pavilion, and now hopes to accommodate a total of 71,000 people, according to sources.

Although the official sites haven't been announced, the committee is finalizing negotiations with the Kennedy Center, the D.C. Armory, the National Building Museum, Union Station, the Washington Sheraton Hotel, the Washington Hilton Hotel, the Omni Shoreham, the National Air and Space Museum and the D.C. Convention Center, the location of two dances. The Convention Center will also be the site of the MTV Ball the same night. In 1989 the same locations, not including the Post Office, were used by the Bush administration for 10 official balls.

The committee will announce the locations of four inaugural dinners set for Jan. 18 and is fine-tuning agreements with the Washington Hilton, Sheraton Washington, National Building Museum and the Convention Center.

On top of this will be the unofficial events, including numerous private receptions and luncheons that have yet to be announced but whose existence can be gleaned by the numerous locations that have been reserved. The National Museum of Women in the Arts, for instance, has been signed for eight events.

There are probably several reasons for the outpouring of enthusiasm, not the least of which is the 12-year Democratic drought. Indeed, some would say the social dry spell was even longer, considering the low-key "People's Inaugural" for Jimmy Carter in 1977. These new Southerners, it would seem, are in the mood for a more levitating kind of hospitality. There's also the larger party appetite of the 18- to 25-year-old voters who were energized by this campaign and the symbols of their generation used by Bill Clinton and Al Gore. And the cultural and musical tastes of the two, who mirror the experiences of the post-World War II television and rock generation, make for varied entertainment prospects. Among the entertainers, committee sources say, look for Mister Rogers, as well as Fleetwood Mac.

Tens of thousands of people are expected to pour into the Washington area for six days of events beginning Jan. 16. Presidential committee planners predict as many as 250,000 for the Sunday, Jan. 17, ceremony on the Mall opening the week's festivities, if the weather cooperates. The committee has set aside 10,000 reservations for inaugural dinners, 18,000 seats at Capital Centre for each of two nights of the Inaugural Gala variety show and 4,000 for two family shows at the Kennedy Center.

But the number of unofficial events and the first-time status of many sponsors have added to the unprecedented nature of the week. The Gay and Lesbian Victory Fund was organized to mount a tribute to David Mixner, a successful fund-raiser and ad hoc liaison to Clinton from the gay community.

A vegetarian society is planning a gala. People for the Ethical Treatment of Animals (PETA), long an aggressive animal rights group, feels it may find some respect within the Clinton camp. "We hope the new administration will take this more seriously. Al Gore has been a proponent of the ban of testing cosmetics on animals," says Dan Mathews, director of the group's international campaigns. PETA has asked the chefs at the Willard Intercontinental Hotel to prepare a veggie affair for Jan. 19. The guests have been asked to pay $250 and to leave their fur coats at home. Mathews said among those expected are singer k.d. lang, poet Rod McKuen, actors Lindsay Wagner, Alec Baldwin, Kim Basinger, Elvira and Kevin Nealon, and baseball manager Tony LaRussa.

For the first time, George Washington University has planned a ball the night of the inauguration. "It is an exciting time in Washington and a lot of students come to George Washington because of their interest in politics," says university spokesman Michael Freedman. The tab is $20, the dinner is all-American, the music is King James & the Serfs of Swing and the invited guests include students and their parents, members of Congress and residents of the Foggy Bottom community.

Georgetown alumni, who can claim Clinton as one of their own, have planned several events, including a pre-ball dinner at their old watering holes, F. Scott's and 1789.

Some standard auxiliary events of Inauguration Week are returning. The American Legion will hold its traditional ball at the Capital Hilton. In the past either the president or the vice president has stopped by.

To add to the social merry-go-round, the Clinton and Gore families will have official schedules. A luncheon for the families of Al and Tipper Gore is planned for Jan. 19. For this event, the committee selected the Lincoln Gallery, a historic room on the third floor of the old Patent Office Building, which Walt Whitman called the "noblest of Washington buildings." The building, at Eighth and G streets NW, is now the home of the National Portrait Gallery and the National Museum of American Art. The site of dinners and receptions since its renovation in the 1960s, the gallery hasn't been used for an inaugural event since the ball of President Lincoln in 1865.

A separate agenda has been planned for Arkansans. It kicks off with a star-studded "The Absolutely Unofficial Bluejeans Bash" at the National Building Museum on Jan. 17. Planned are luncheon fashion shows, a dance featuring half brother Roger Clinton's band, cocktail parties and brunches.

Celebrities involved with the official programs are starting to build their own calendars. Maya Angelou, who is writing a poem for the swearing-in ceremony, will be the focus of a brunch sponsored by Conrad and Peggy Cooper Cafritz, local arts patrons, Elle magazine and Johnnetta Cole, president of Spelman College.

The quadrennial rounds of the various state societies start on Jan. 16 with the massive event of the Texas State Society at the Sheraton Washington. Called "Black Tie and Boots," this dance has been held every inauguration since Bush won the vice presidency in 1980. Planning for more than a year, the society watched the fortunes of Texas rise and fall during the campaign and, now that all the dust has settled, will honor Lloyd Bentsen, the treasury secretary-designate. At $75 a ticket, all 6,000 have sold and Mark Chestnut, Holly Dunn and Asleep at the Wheel are set to entertain. Indiana and Illinois are planning balls for Jan. 19 and have hired the society bands of Gene Donati and Lester Lanin.

Where the Clintons will go during the week has not been released but many people are betting one stop will be the gay and lesbian event. Victory Fund organizers have already met their cutoff of 1,000 people and have set up a waiting list. "The Los Angeles contingent alone has been ordering tickets like crazy," says William Waybourn, the group's executive director. "We have confirmations from David Geffen, Barry Diller, Skip Paul. We have been overwhelmed."

Speaking perhaps for many others in the inaugural organization business, he adds: "It is a nice problem to have, but I am not sure what we are going to do."