The support and devotion of Serge Koussevitzky, who published Dukelsky's chamber music and conducted his orchestral scores, helped him develop his more classical works. Dukelsky's concerto for piano, orchestra and soprano obbligato titled "Dédicaces" (1935–1937), was premièred by Koussevitzky and the Boston Symphony Orchestra in January 1939 in New York. His oratorio, "The End of St. Petersburg", was premiered a year earlier by Schola Cantorum and the New York Philharmonic under Hugh Ross. In 1937, the composer was asked to complete Gershwin's last score, a soundtrack to a Technicolor extravaganza "The Goldwyn Follies", for which he contributed two parody ballets, choreographed by George Balanchine, and a song "Spring Again". In 1939, Dukelsky became an American citizen and took Vernon Duke as his legal name. Duke's greatest success came a year later, with the Broadway musical "Cabin in the Sky" (1940), choreographed by George Balanchine and performed by an all-black cast at the Martin Beck Theater in New York.