A musician long before she became an academic and then a world-famous diplomat, Secretary of State Condoleezza Rice (search) took to the Kennedy Center concert stage Saturday to accompany a young soprano battling an often-fatal disease.

Rice's rare and unpublicized appearance at the piano marked a striking departure from her routine as America's No. 1 diplomat. A pianist from the age of 3 she played a half-dozen selections to accompany Charity Sunshine (search), a 21-year-old singer who was diagnosed with pulmonary hypertension a little more than a year ago.

The soprano is a granddaughter of Rep. Tom Lantos, D-Calif., and his wife Annette, who Rice has known for years. The Pulmonary Hypertension Association (search), formed in 1990, presented the concert to draw attention to the disease from which more than 100,000 people are known to suffer.

Largely unknown in the United States until about 10 years ago, it has no known cause or cure, but genetic studies and a search for treatment are under way.

Sunshine has persisted in her career and performed with orchestras in Hungary, her grandparents' home before the Holocaust, Denmark and the United States. On Saturday, in a concert entitled, "An Evening of Music, Friendship and Awareness" and hosted by Lantos, she drew the secretary of state to play selections by Verdi, Mozart and Jerome Kern.

Eileen Cornett, of the Peabody Conservatory in Baltimore, Md., accompanied Sunshine on a half-dozen other pieces.

Lantos introduced Rice as "a warm friend" and said the concert was her idea, describing how her eyes filled with tears as he told him about his granddaughter's illness.

"We have to do something about this and enhance public consciousness," he quoted Rice as saying. "Let's have a concert and I will accompany her at the piano."

Rice, whose first name is a variation on the Italian musical term "con dolcezza," which is a direction to play with sweetness, learned to read music at the age of 3.

As a child she performed, won piano competitions and planned a career as a a concert pianist. But she switched her field of interest to international relations in her junior year at the University of Colorado and went on to be provost at Stanford University, then President Bush's assistant for national security, and now secretary of state.

Despite her busy schedule, Rice finds time to enjoy classical music and plays occasionally and privately with friends in a string quartet.

In February, on a trip to Europe, she visited a Parisian music school, Conservatoire Hector Berlioz, after a session with French political elite.

Rice tapped her toes to keep time as a music teacher led a group of students age 7 to 9 through their scales. She told the youngsters, "It takes a lot of work to learn to read music. You have to practice and practice and practice."

Among those in the Kennedy Center audience were U.N. Secretary-General Kofi Annan, eight ambasssadors to the United States, Librarian of Congress James Billington, National Institutes of Health director Elias Zerhouni and Undersecretary of Defense Douglas Feith.