Over five decades, composer Carl Orff and colleague Gunild Keetman established a compendium of short didactic pieces that introduce basic musical concepts to very young children. Most of these involve simple rhythm instruments, such as clapping hands, but more often xylophones, glockenspiels, triangles, drums, and bells. The recorder is introduced early on and several of the more advanced pieces involve violin and cello, and there are also many items for speaker or singer and unaccompanied choir. The series begins with simple rhymes, rhythmic exercises, and pentatonic scales, and concludes with more complex material, including fairy tales, Goethe excerpts, and use of seven-note scales. Because much of the Orff method emphasizes improvisation, performances and recordings of the music vary greatly in instrumentation and structural details. The most famous piece is called Gassenhauer, or Street Song. It's actually a Keetman arrangement of a 1536 song by Hans Neusidler, beginning with a simple rhythmic foundation onto which is gradually layered other straightforward percussion lines, in a way that creates what sounds like a complex, vibrant crescendo.
The project began in the 1920s when Orff became interested in renewing music through its partnership with movement -- not only in such concert works as Carmina Burana, but in educational pieces as well. Orff was influenced by Curt Sachs, the director of Berlin's State Collection of Musical Instruments, who emphasized rhythm as the foundation of musical and bodily expression. The project fell into place in 1924 when Orff began teaching music courses at Dorothee Günther's new school of modern dance and movement in Munich. Orff initially focused on the use of hand clapping, foot stomping, and finger snapping along with homemade rattles and some hand drums and tambourines. Piano exercises shortly entered the curriculum, emphasizing improvisation using pentatonic scales. Keetman joined the school in 1926 and was soon writing pieces centering on the xylophone and recorder, as well as conducting the school's dance orchestra. Piano builder Karl Maendler began designing simple mallet instruments especially for the music program and these Schulwerk instruments are now employed with the Orff method around the world.
The music-and-movement exercises were first published in 1930 under the title Orff-Schulwerk: Elementare Musikübung. These "elementary music works" were scheduled to be introduced into Berlin's elementary school curriculum, but the Nazi takeover and ensuing war destabilized the system and the Günther school itself was closed in 1944. After the war, Bavarian Radio's director of educational programming cajoled Orff and Keetman into producing a series of radio programs featuring music children could play along with at home. At this point -- 1948 -- the composers turned their attention to children's songs and rhymes, drawing material from Franz Magnus Böhme's 1897 collection of 6,000 German children's songs. Largely as a result of these programs, a new, five-volume edition came out in 1950, now called Orff-Schulwerk: Musik für Kinder. This became the basis of the Orff program, although pieces would continue to be added for nearly 30 more years.