Soviet ballerina Maya Plissetskaya, still dancing at age 64, says she'll leave the stage forever only when audiences stop responding. "If I feel I can't give people anything, then I will quit without regret," she said. Plissetskaya, whose performances in "Swan Lake," "Carmen" and "Don Quixote" were benchmarks, recently appeared in Buenos Aires in a ballet by Argentine composer Astor Piazzolla. She began dancing at age 4 and entered the Bolshoi's ballet school at 8.