Before pianists Margaret Patrick, 74, and Ruth Eisenberg, 85, found each other in the spring of 1983, both had despaired of ever being able to play music again. The year before, they had suffered strokes that left them partly paralyzed; Margaret lost the use of her right hand, Ruth the use of her left. While recovering at the Southeast Senior Center for Independent Living in Englewood, N.J., Ruth sat at the piano noodling with her right hand but mostly feeling sorry for herself. Then one day a therapist introduced Ruth to Margaret, who joined her at the keyboard and began playing a left-hand accompaniment. Suddenly the sound of Chopin's Minute Waltz drifted through the center. Recalls Ruth: "We both experienced euphoria."

Under the stage name Ebony and Ivory, the two great-grandmothers now play at the center every week, drawing on a classical repertory and sing-along favorites like Down by the Old Mill Stream. Margaret, a slender and stately widow, was weaned on both classical and gospel music in her native Harlem and once accompanied Duke Ellington and his orchestra during a 1968 church performance. Ruth, a roly-poly white-haired jokester from New Jersey, says she "inhaled all the fine music by osmosis" from her late husband, Jacob Eisenberg, who wrote textbooks for piano teachers. In performance Margaret provides harmonies while Ruth handles the melody line. "When I fumble because of my arthritis," Ruth says, "Margaret improvises."

Ruth jokes that the duo's success is a result of all the things she and Margaret have in common: "We're both Geminis—the twins—and we're both the same sex, right?" Margaret says that Ruth gives her self-confidence; Ruth says that Margaret gives her peace of mind. And both believe that their union is more than just a musical partnership. Says Ruth: "It was really an act of God."