"Looking back over 50 years, I'll tell you what, this is it, this is the last anniversary," Therrell Smith was saying, seated with hands in her lap at a long dining table in her elegant home on Logan Circle.

She was preparing for a ballet recital to mark her half-century as dance teacher and promoter of high moral standards. The program is scheduled for 7:30 p.m. Friday in the Crampton Auditorium at Howard University. At age 79, Smith will be featured in a duet with one of her finest students, Virginia Johnson, the retiring prima ballerina of the Dance Theater of Harlem.

"The world has changed so much, and people just don't have time for this sort of thing anymore," she mused.

The prospect of performing with Johnson, whom Smith taught for 10 years beginning when Virginia was just 3, excites her.

But organizing a 50th anniversary extravaganza, which includes the recital, a lavish dinner-dance at the University of Maryland Inn the next night and an old-fashioned family picnic in Rock Creek Park on Sunday -- while operating the Therrell C. Smith School of Dance and teaching all the classes -- can get to be a bit much.

"It used to be that if you wanted to get the word out about a recital, you just told the students and everybody showed up," Smith said.

"Nowadays, people are so bombarded with mail that they don't even look at half of it. You need a computer and e-mail to communicate, which I don't have, and that's not even a guarantee because people are so busy trying to raise their children and buy homes and have careers."

It all seemed so much simpler back in 1948.

Smith had recently graduated from Fisk University in Nashville, with a bachelor's degree in sociology.

She had wanted to become a social worker, but during a visit to a nursery school run by her sister, Mathilde, a parent asked Smith if she would teach ballet to some of the children in the school.

"A light went on in my head, and I gave up on social work and dancing became my career," she said.

Smith had started taking ballet lessons at age 8 from a local teacher named Mabel Jones Freeman. She later studied ballet in Paris under the tutelage of a Russian prima ballerina and spent five years studying dance with the Ballet Arts at Carnegie Hall in New York.

Her father, T.C. Smith, was a prominent physician who believed strongly in business and property ownership. For him, having a daughter teach dance wasn't good enough; he wanted her have her own school.

So, as soon as a law was passed lifting restrictions against blacks buying property previously owned by a white, he purchased a building in the unit block of Rhode Island Avenue NW and turned it into a dance studio.

"The whites started moving out almost immediately," Smith recalled. "They thought I was going to turn their block into another U Street," which was then a predominantly black entertainment strip.

What Washington lacked in racial harmony at the time, Smith recalled, it made up for with a unique sense of community among the black middle class.

"Dance lessons for little girls was almost a requisite for the middle class during that period," Smith said. "These were the days of Duke Ellington and Count Basie, of refinement, grace and style. There was no doubt in the minds of black people back then that they were as good as, if not better than, anybody else."

Times sure have changed. With the advent of integration, black girls can now go anywhere they want for dance lessons. As a result, many of the social networks that grew up around Smith's dance school, including the birthday parties and holiday teas, have all but disappeared.

To make her expertise available to more than just the children of the black middle class, she began volunteering as a dance teacher with D.C. public schools.

In 1959, she moved her school to larger quarters on Bunker Hill Road NE. And in 1974, she started the Thomas and Birdie C. Smith Arts Foundation, named for her parents, to introduce young people throughout the city to classical and interpretive dance.

In 1995, the foundation began sponsoring a "Beautillion," a celebration of the achievements of male high school seniors who distinguish themselves academically. Each young man receives $1,000 toward his college education.

Thousands of students have come through Smith's dance school doors, but there is one whose arrival nearly 50 years ago she remembers as if it were yesterday.

"Virginia Johnson moved across the stage with such grace and feel for movement that I knew immediately that she was a real ballerina," Smith said.

These days, the two are supposed to be rehearsing for Friday's recital. But Johnson hasn't made it down to Washington yet from New York, and Smith has had her hands full with preparations for the other events this weekend.

"We're supposed to dance," said Smith, sounding doubtful. "I know it sounds funny, since I'll be 80 years old in November, so we'll just have to see what happens."

Still flexible as a willow's limb yet strong as an oak, Smith can lift her leg up to a ballet barre and touch her knee with her head. That alone suggests that the only statement of hers that is really in doubt is when she claims that this anniversary will be her last. CAPTION: Therrell Smith, 79, will mark 50 years of teaching dance with a recital Friday that will include ballerina Virginia Johnson.