Liberties

 I An old theory has it that the most important architects of classical ballet have all been émigrés. In the late Renaissance and early Baroque eras, when ballet became primarily an art of the French courts and acquired some of its enduring characteristics, it was shaped by dancing-masters and composers from Italy. The most influential choreographer and theorist of the second half of the mid-eighteenth century, Jean-Georges Noverre, the foremost proponent of ballet as an art of dramatic expression, was French but had his greatest successes in Stuttgart and London. In Russia, in the late nineteenth century,  Marius Petipa, whose choreography did much to bring ballet to a new peak, came from France. Much of the most vital work in twentieth-century ballet was achieved by Russians who came along in Petipa’s wake — Mikhail Fokine, Vaslav Nijinsky, Leonide Massine, Bronislava Nijinska, George Balanchine — and came West with the art that they had learned in the fatherland. London’s Royal Ballet, which became the most internationally acclaimed of Western companies for decades after the Second World War, was the creation of Ninette de Valois and Frederick Ashton: de Valois was an Irishwoman who adopted a French name but always spoke of “the English style,” Ashton an Englishman who had been born in South America (where he first saw ballet and became a convert) and told generations of dancers, “Stop being so stiff and English.” Let’s not turn this migration theory into a formula, though. Several great choreographers have stayed in the land of their birth; many bad ones have swapped countries. Yet today Alexei Ratmansky — a choreographer who has held Ukrainian, Russian, and American passports — is a case study for any theory about classicism and migration. His life and career have been startlingly interlocked with major chapters of modern