Even a drenching precurtain downpour hardly dampened the excitement at Philadelphia's open-air Mann Music Center. Mikhail Baryshnikov was back, returning for his first U.S. performance since a knee injury put him on the disabled list last February. Almost everyone in the packed house knew that the 34-year-old Soviet-born superstar had undergone surgery to remove damaged cartilage in his right knee, the sort of thing that might have destroyed the onstage careers of other dancers his age. And though he made a courageous comeback in July at Spoleto, Italy—"I think it went okay," he said, "I'm happy about it"—he confessed that his knee swelled and sometimes caused him pain. But as an associate marveled, "Misha has a body made to dance," and he proved it again. Baryshnikov brought opening-nighters at his American Ballet Theatre premiere to their feet with the pas de deux from the Balanchine-choreographed Harlequinade. Critics agreed. Noted the Philadelphia Inquirer's Valerie Scher: "He is still capable of the dizzying turns, high-flying leaps and a precision that sets him apart."