With his cello tucked under one arm, and a box of yellow roses under the other, world-famous Russian cellist Mstislav Rostropovich stepped into the Ted Kennedy house in McLean, Va. The 175 assembled guests broke into applause. Rostropovich smiled, presented the flowers to sun-tanned Joan Kennedy and gave her a bear hug. ("My feeling was to hug him right back," she said later.) "Thank you, thank you," Rostropovich boomed in accented English, "for all the things you have done for me and my wife." So saying, the cellist grasped the startled senator cheek to cheek and squeezed him in gratitude too.

That mellow mood lasted the length of the two-hour reception which followed the first of five Rostropovich recitals in Washington. For years he had been prevented by the Soviet government from performing in the West because of his support for now-exiled author Alexander Solzhenitsyn. Then last April the Kennedys journeyed to Moscow. Joan, a talented amateur pianist, raised the possibility of a Rostropovich tour with two Soviet officials. Senator Kennedy echoed his wife's plea during his four-hour talk with Leonid Brezhnev. "I'll look into it," the Soviet leader waffled. But within days, the cellist had a two-year visa. (The Rostropoviches—she is soprano Galina Vishnevskaya—have settled in Lausanne, Switzerland.) "We may have been instrumental," Joan admitted cautiously, "in bringing him here."

Guests at the Kennedy party included Henry Kissinger, painter Jamie Wyeth, Washington gadabout Barbara Howar and a near quorum of senators and representatives. They drank, red and white wine and devastated a buffet of deviled eggs, roast beef, chicken a la king and Camembert.

When Kissinger arrived (without Nancy, who had the flu), he apologized for missing the recital: "I'm a great admirer, but I had to work tonight." Kissinger then said he would miss the other concerts because he had to return to the Middle East. "You travel too much," Rostropovich joked. Some congressmen who agree perked up their ears.

Kennedy managed to pry Rostropovich's cello from the 47-year-old artist and escorted him arm-in-arm on a tour of the home—and through goodnight kisses to the Kennedy children in bed. "Big deal," sighed Kara, 15, the only Kennedy child allowed up that late. "Who wants to see Patrick sleeping?" (Patrick is 7 and did not wake up.)

At 1:30 a.m. Rostropovich and Galina said goodbye. Joan Kennedy waved them into the chilly night, then turned to the buffet table for her first nibbles. She had nothing to drink all evening. The weary senator meanwhile had slipped off to bed.