WITH THE ROAR of the crowds and an all-points groundswell of community pride and support, Greater Washington is rallying in wonderful ways behind the sure-fire winners at the Rose-Bowl this coming New Year's Day. We refer not to a football team, but to the talented young men and women of the award-winning "Crowd-Pleasin' Band" from Washington's Cardozo High School. If -- and it's still a big if -- all continues to go well, they will strut their stuff as never before for the estimated 125 million people who watch the parade on television from Pasadena.

That the Cardozo band will knock the socks off anybody who watches it on that day is not in question. And so far, people and organizations from every corner of this community have been pulling out all the stops to raise what it takes to outfit, transport and cover the city's 170 representatives on their trip. Over a decade, parents, friends and fellow students have been working furiously to raise money for the band, which grew from a cluster of students in windbreakers and white pants to star performers in the grand bicentennial parade on the Fourth of July '76.

For the band members under the guidance of director Robert Gill, it has meant hours of hard work -- two hours before classes every day, again during lunch periods and two more hours after school. But it has also meant music scholarships, achievements and a well-earned sense of importance.

But back to the question of money, and it's big money this time -- more than all the continuing car washes, picnics and other neighborhood efforts can raise. It will take more than $100,000 to do the job, but the campaign has already brought in about $50,000 from individuals, citizens' groups, generous people in Pasadena and a string of citywide fund-raising events sponsored and supported by local groups, including stations WHUR and WMAL, the Washington Afro-American, members of the Greater Washington Board of Trade and an areawide coalition organized as the Cardozo Rose Bowl Committee.

To meet the most pressing bills -- which must be paid by mid-October -- the Committee and WHUR are sponsoring a benefit concert wth Peaches and Herb and Mtume, in the Kennedy Center Opera House on Monday, Sept. 29. A sellout would over those immediate expenses. So now it's a matter of going that tough last mile; all this impressive local spirit and work could be crushed if the final events are ignored. Whether it's the concert, the roses that band members will be selling at the Soccer Bowl and Redskin games, the fund-raising dinner with Channel 9's J. C. Hayward next month, gatherings held by smaller groups such as "The Mouf" newsletter or other events planned in the coming days, the continued response of people all around town will determine how much a city appreciates its young, gifted and proud achievers. They deserve the big opportunity that is now so nearly in their grasp.