Aaron Copland's Third Symphony, completed in 1946 after some two years of concentrated labour, comes at the end of more than a decade during which his orchestral efforts were either in response to commissions in the field of ballet (Billy the Kid, Rodeo and Appalachian Spring) or cinema (Our Town), contrived to underline spoken text (Lincoln Portrait) or transmit impressions of travel (El Salón México, Danzón Cubano) or otherwise restricted by exterior factors (e.g., Second Hurricane and Outdoor Overture, intended for performance by school children). The degree to which he maintained his integrity and the quality and self-subsistence of his music through all these pièces d'occasion is quite astonishing. But it is, all the same, highly gratifying, and in the realm of the most notable musical occurrences, that he has finally found the leisure (through a commission from the Koussevitsky Foundation) to write a full-length symphony (some forty minutes in duration), a work that has not, either in seriousness or dimension, been obliged to compromise in the slightest with an impresario or any other demands of an occasion or dramatic situation.