Mr. Washington, who runs the Laundromat, hasn't played the piano since he lost his daughter and his sight in a car accident, but he takes an interest in Ephram, a young violinist he hears playing Bach on the apartment roof on summer nights. After Ephram finds out how much Mr. Washington can tell about him by listening (``light step, brush, must be Ephram walking home from his violin lesson, stepping glad''), the old man urges him to take part in a neighborhood concert. Ephram is reluctant to play in public; but when the lights fail, he uses the opportunity to get his friend to join him in a duet. The denouement of Barrett's first children's book is predictable but her telling is lovely, drawing on the cadences of African-American English and using vivid imagery based almost entirely on sounds. Speidel depicts the characters with tenderness and intelligence; her lush, soft-edged pastels are the perfect medium for these luminous night scenes. Warmly appealing. (Picture book. 5-10)