Bach was himself a prodigious talent at the keyboard, well-known during his lifetime both for his technical abilities and for improvisation. Many of Bach's keyboard works started out as improvisations.
During the long period of neglect that Bach suffered as a composer after his death extending to his rediscovery during the nineteenth century, he was known almost exclusively through his music for the keyboard, in particular his highly influential pantonal series of Preludes and Fugues in the Well-Tempered Clavier, which were regularly assigned as part of musicians' training. Composers and performers such as Ludwig van Beethoven and Camille Saint-Saëns first showed off their skills as child prodigies playing the entire cycle of Bach's 48 Preludes and Fugues.
Modern composers have continued to draw inspiration from Bach's keyboard output. Dmitri Shostakovich, for example, wrote his own set of Preludes and Fugues after the Bach model. Jazz musicians and composers, in particular, have been drawn to the contrapuntal style, harmonic expansion and rhythmic expression of Bach's compositions, especially the works for keyboard.
Many of Bach's works for keyboard were published in Bach's own lifetime, by the composer himself, under the title Clavier-Übung (Keyboard Practice) I-IV. The first volume, Bach's Opus 1, was published in 1731, while the last was published a decade later. The volumes are an open imitation of two volumes published by Bach's Leipzig predecessor Johann Kuhnau under the same title. Kuhnau used arrayed keys to structure his exercises, a model which Bach emulated through the Clavier-Übung volumes. The Well-Tempered Clavier, however, was not published until half a century after Bach's death, although they were in circulation before that in manuscript form. Of the four Clavier-Übung works, the first, second and last contain music written for harpsichord, while the third is devoted to compositions for organ.