In May 1943, Serge Koussevitzky commissioned Béla Bartók to write a major work for the Boston Symphony Orchestra, of which he was music director. Bartók was well regarded as a composer and pianist, and he had settled in the United States in 1940 to escape the dangerous climate in Europe. Since his arrival, he had been welcomed by the academic community, through an honorary doctorate from Columbia and numerous invitations to teach and perform, but he had done very little composition. In addition, he was undergoing periodic hospitalization for leukemia (although this was originally misdiagnosed), the disease that would kill him little more than two years later. Nonetheless, he responded energetically to Koussevitzky’s request. He created a piece that, while essentially symphonic in its structure, uses the orchestra less traditionally than would be expected in a piece labeled "Symphony," given the long (and generally conservative) history of works so named. Specifically, the piece gives each individual section in the orchestra its opportunity to shine, putting particular emphasis on instrumental color and virtuosity. In recognition of the work’s unusual disposition, Bartók gave it the title Concerto for Orchestra, creating a new genre in the process. Many composers have since written works with the same title; of these, the best known is that by the Polish composer Witold Lutoslawski. Bartók’s piece was an instant success and has gone on to become his most popular orchestral work.
Early in Bartók’s composing career, he had difficulty establishing his distinct compositional voice, instead producing works that showed too clearly their debt to Liszt, Wagner, and Strauss. (His interest in Strauss’s music is perhaps the most surprising, and it manifested itself in more than one way: in his early twenties, he gained considerable notoriety through performances of his own piano transcription of Strauss’s massive orchestral tone poem, Ein Heldenleben.) As his progress as a composer stalled, he explored new possibilities, discovering inspiration in the folk music of Hungarians, Romanians, and Slovaks. He came to see rural peasants, who were less subject to the encroachment of Western cutural trends, as the true carriers of Hungary’s musical identity. Through his rapidly developing interest in the subject, he developed an important friendship with Zoltán Kodály (1882-1967), a young composer who already knew a great deal about indigenous folk music. Concerned with capturing the music in as authentic a setting as possible, he took the (recently invented) phonograph to Transylvania in 1907, recording the songs of people there so that could later transcribe what he had heard. His ethnomusicological studies were important to him throughout his career, and they had a profound influence on his development as a composer. His mature style relies heavily on the spirit of folk song, often employing actual songs in an "artistic" setting, or at least constructing melodies with a strong, native "vocal" character.
Bartók was also creative in his approach to musical form. He sometimes wrote in what is called an "arch form" – a musical structure in which the first and last sections are similar, the second and second-to-last sections are similar, and so on, with the central section usually being an emotional turning point. The Concerto for Orchestra fits this pattern well. Of the five movements, the first and last are the longest and loudest, they contain the grittiest music (and the greatest challenges for the musicians), and they each have F as an overall tonal center. Each of these movements also pits two styles of dance – one vigorous, the other reflective – against each another. The second and fourth movements are much lighter in character, and they use the orchestra more sparingly. Pairs of wind instruments, starting with the bassoons, take turns in the spotlight during the second movement, which is entitled "Game of Couples." Humor is noteworthy in the fourth movement, both in the lilting (yet irregular) main melody and in the exaggerated, circus-like interruption two-thirds of the way through. The central movement is the most fascinating of the piece. Fluttering woodwind and string effects create an eerie landscape, against which lonely solo wind voices (particularly the oboe, piccolo, and horn) call out in search of companionship. Material from the first movement’s introduction is also brought back, providing unpleasant reminders of previous conflicts, but finally giving way to a hypnotized stillness. The tension remains, only to be broken by the fourth movement and chased away by the finale.