From 1905 he travelled the villages of Hungary, Romania and North Africa with Kodály and a wax-cylinder recorder, collecting more than ten thousand folk songs. This was not a hobby but systematic ethnomusicology; he is one of the founders of the discipline.
Those recordings went straight into his language: asymmetrical metres, modal writing, and the texture of insects and distant sounds he called night music. His structures are often symmetrical — the first movement of the Music for Strings, Percussion and Celesta is a fugue that expands outwards from the middle of the register in both directions. He emigrated to America in 1940 to escape the war and died poor and ill there. The Concerto for Orchestra is his last large work and the easiest way in.
