Keyboard Works (Klavierwerke) by Johann Sebastian Bach typically describes the Nos. 772 to 994, Chapter 8 in the BWV brochure, noting compositions for a solo keyboard instrument like the harpsichord or the clavichord. Despite the fact that organ is likewise a keyboard instrument, which in Bach’s time the difference wasn’t constantly made whether a keyboard structure was for organ or another keyboard instrument, Wolfgang Schmieder varied organ compositions in a separate section of the Bach-Werke-Verzeichnis (Nos. 525-771). Also other structures for keyboard, like structures for lute-harpsichord and fortepiano were noted outside the “Klavierwerke” variety by Schmieder. Lute works remain in the variety 995– 1000, Chapter 9 in the BWV catalogue.
Bach was a prodigious skill at the keyboard, well known during his life time for both his technical and improvisational abilities. A number of Bach’s keyboard works started as improvisations. Bach wrote extensively for the harpsichord, producing various developments, suites, fugues, partitas, overtures, in addition to keyboard arrangements of concerto music by his contemporaries. The fortepiano is an instrument Bach would have encountered once, by the end of his life when it was just recently developed, while visiting his boy in Potsdam. The go to led to Das Musikalische Opfer, parts of which might have been meant for the brand-new instrument.