Midway through her 103rd birthday party Sunday, Rosina Tucker went to the piano to play and sing for the 200 friends who had gathered at the Fifteenth Street Presbyterian Church for the celebration.

The song was "November Rose." Her friends were not surprised, for Tucker, walks erectly and still revels in being a social activist.

She travels often to talk about her passions -- the problems of the elderly and the history of the formation of the International Brotherhood of Sleeping Car Porters, the first labor organization established by and for blacks.

The birthday celebration for Tucker, who was born in Washington in 1881, has become a tradition at the Northwest church where she has been a member since 1917. Tucker, who has no children and no relatives, is the church's oldest member.

This year, as in the past, church members prepared the birthday banquet which featured platters piled high with turkey and dressing, corn and string beans. Later Tucker, her slight frame, dressed in a full-length lavender dress with a ruffled collar, cut a birthday cake with white icing and the numbers 1-0-3.

"I've known Rosina for the greater part of 30 years," said Norma McDaniel, one of Tucker's closest friends.

"She always says she wishes her body could work as well as her mind. She's a quick thinker."

Rosina Tucker, whose head is covered with snow white hair, has conceded little to her age.

She still fixes her breakfast every morning, cleans her home and writes her speeches.

But now she always travels with a companion whether it's a trip to the grocery store or across the country to give a speech. And the church members are always there to lend a hand. Her husband died in 1960.

"The other morning when I got up, I looked out the window and there was a lady from my church with her three children cutting my grass and cleaning off my back yard," Tucker said.

"I didn't ask them to do it, but my church has always been solicitous when it comes to helping me."

Later she added, "I believe religion is very important in a person's life . . . . I've been almost every place I ever wanted to go, met many interesting people and basically had a good life. But that doesn't mean I'm ready for the Man to come get me!"

A few weeks ago Tucker testified before the Senate Labor and Human Subcommittee on Aging, which was gathering information on longevity.

Tucker said she had no special secrets. "Most of my family lived to their mid- to late-80s," she told subcommittee chairman Claiborne Pell (D-R.I.).

"My great grandmother lived to be 101, my father died in his 50s and my grandparents lived until they were in their mid 90s. I don't know why we live so long," she said.

Over the years Tucker has testified before Senate and House committees on labor, voting rights for the District, education and day care. She also lobbied the Congress for labor and education legislation and helped organize unions for laundry workers and domestics.

She tells audiences that their elderly neighbors need their help, because most senior citizens live alone.

She says she is better off than most her age because of her friends.

Her two-story brick home on Seventh Street NE has changed little since it was used as a birthplace for the International Brotherhood of Sleeping Car Porters more than 50 years ago.

Tucker spends a great deal of her time traveling around the country telling the history of the formation of the Pullman porter's union. Two years ago she narrated an hour-long public television documentary on the union's history.

She got involved in the union because her husband Berthea J. Tucker, whom she married in 1918, was a Pullman porter.

In those days a job as a Pullman porter was one of the best available for a black man.

The porters worked in the Pullman sleeping coaches, making beds, shining shoes and collecting hefty tips.

"To be a Pullman porter in those days meant respect, prestige, social status and prominence," said Tucker, gritting her teeth and straightening her back.

The labor movement was just gaining strength in this country, but labor organizing was dangerous and difficult work.

It was particularly dangerous for blacks.

"We ran into fierce opposition from the powers that be, as well as some of the porters," said Tucker, who first heard of the organizing efforts from friends who had come to visit her husband.

"The men were afraid to talk union for fear of losing their jobs or worse," she said. "In the meeting hall the women had to do the talking and distribute literature. The people of the Pullman Company wouldn't dare touch us. We were the backbone in organizing the Brotherhood of Sleeping Car Porters."

Her allegiance to the union soon led to her appointment as the liaison person between Washington and A. Philip Randolph, the union's major organizer in New York.

Randolph, a radical magazine editor and social theoretician first reported on the movement and then went to work with Ashley Totten, a porter, who started organizing the porters in 1925.

The Pullman Co. signed a contract with the new union in 1937.

Neither the struggle for social change, nor the struggle to live a good life are overnight propositions, according to Tucker.

"You don't come to living this long by starting to live well at an old age," Tucker said. "You start when you are born and you work your way up to it. It isn't easy."