to stay fairly uncomplicated. Around the turn of the century, however, harmonic and metric devices became either more rigid, or much more unpredictable, and each approach had a liberating effect on rhythm, which also affected ballet. Diaghilev was a pioneer in adapting these new musical styles to modern ballet. When Ravel used a time in the final part of his ballet Daphnis and Chloe (1912), dancers of the Ballets Russes sang Ser-gei-dia-ghi-lev during rehearsals to keep the correct rhythm. Members of Diaghilev's Ballets Russes later went on to found ballet traditions in the United States (George Balanchine) and England (Ninette de Valois and Marie Rambert). Ballet master Serge Lifar went on a technical revival at the Paris Opera Ballet, enhanced by Claude Bessy and Rudolf Nureyev in the 1980s. Lifar is credited for saving many Jewish and other minority dancers from the Nazi concentration camps during World War II. After dancing with the Ballets Russes in 1925, Ruth Page emerged as a founder of her own ballet troupes based in Chicago, including the Chicago Opera Ballet. Personal life Diaghilev's life and the Ballets Russes were inextricably entwined. His most famous lover was Nijinsky. However, according to Serge Lifar, of all Diaghilev's lovers, only Léonide Massine, who replaced Nijinsky, provided him with "so many moments of happiness or anguish". Diaghilev's other lovers included Anton Dolin, Serge Lifar and his secretary and librettist Boris Kochno. Nijinsky's later bitter comments about Diaghilev inspired a mention in W. H. Auden's poem "September 1, 1939": What mad Nijinsky wrote About Diaghilev Is true of the normal heart; For the error bred in the bone Of each woman and each man Craves what it cannot have, Not universal love But to be loved alone. Diaghilev dismissed Nijinsky summarily from the Ballets Russes after the dancer's marriage to Romola de Pulszky in 1913. Nijinsky appeared again with the company, but the old relationship between the men was never re-established; moreover, Nijinsky's magic as a dancer was much diminished by incipient mental illness. Their last meeting was after Nijinsky's mind had given way, and he appeared not to recognise his former lover. Diaghilev was known as a hard, demanding, even frightening taskmaster. Ninette de Valois, no shrinking violet, said she was too afraid to ever look him in the face. George Balanchine said he carried around a cane during rehearsals, and banged it angrily when he was displeased.