Concerto for Orchestra (Bartók)  The Concerto for Orchestra, Sz. 116, BB 123, is a five-movement orchestral work composed by Béla Bartók in 1943. It is one of his best-known, most popular, and most accessible works. The score is inscribed "15 August – 8 October 1943". It was premiered on December 1, 1944, in Symphony Hall, Boston, by the Boston Symphony Orchestra conducted by Serge Koussevitzky. It was a great success and has been regularly performed since. It is perhaps the best-known of a number of pieces that have the apparently contradictory title "Concerto for Orchestra". This is in contrast to the conventional concerto form, which features a solo instrument with orchestral accompaniment. Bartók said that he called the piece a concerto rather than a symphony because of the way each section of instruments is treated in a soloistic and virtuosic way. The work was written in response to a commission from the Koussevitzky Foundation (run by the conductor Serge Koussevitzky) following Bartók's move to the United States from his native Hungary, which he had fled because of World War II. It has been speculated that Bartók's previous work, the String Quartet No. 6 (1939), could well have been his last were it not for this commission, which sparked a small number of other compositions, including his Sonata for Solo Violin and Piano Concerto No. 3. Bartók revised the piece in February 1945, the biggest change coming in the last movement, where he wrote a longer ending. Both versions of the ending were published, and both versions are performed today. The piece is scored for the following instrumentation. The piece is in five movements: Bartók makes extensive use of classical elements in the work; for instance, the first and fifth movements are in sonata-allegro form. The work combines elements of Western art music and eastern European folk music, especially that of Hungary, and it departs from traditional tonality, often using non-traditional modes and artificial scales. Bartók researched folk melodies, and their influence is felt throughout the work. For example, the second main theme of the first movement, as played by the first oboe, resembles a folk melody, with its narrow range and almost haphazard rhythm. The drone in the horns and strings also indicates folk influence (see example).