In 1924, the restless young man left hospitable America for the Old World. In Paris, he received a commission from Serge Diaghilev to compose a ballet. Dukelsky's first theatrical production, "Zephyr and Flora", was staged in the 1925 season of Ballets Russes, with choreography by Léonide Massine and scenography by Georges Braque, to great critical acclaim. In a review of musical novelties of the season, Sergei Prokofiev described it as full of "superior melodies, very well designed, harmonically beautiful and not too 'modernist'." Prokofiev was as impressed with the young talent as Diaghilev was, and soon the composers became close friends. They frequently saw each other until the end of the 1930s and corresponded until 1946, when the attacks of Soviet officialdom on Prokofiev (who returned to Russia in 1938 although Duke urged him not to go) made the further exchange of letters too dangerous for Prokofiev. Dukelsky's First Symphony was premiered by Serge Koussevitzky and his orchestra in 1928 in Paris on the same bill as the excerpts from Prokofiev's "The Fiery Angel". Some of Dukelsky's and Prokofiev's compositions of the 1930s bear evidence of the sustaining musical dialogue.