Johann Sebastian Bach was better known as a virtuoso organist than as a composer in his day. His sacred music, organ and choral works, and other instrumental music had an enthusiasm and seeming freedom that concealed immense rigor. Bach's use of counterpoint was brilliant and innovative, and the immense complexities of his compositional style -- which often included religious and numerological symbols that seem to fit perfectly together in a profound puzzle of special codes -- still amaze musicians today. Many consider him the greatest composer of all time judging by the character of Bach's early keyboard works, both the improvisatory and virtuoso aspects of his playing acted as spurs to his creativity. Improvisation was essential to the keyboard player's training in Bach's day, and numerous passages in the early keyboard works no doubt had an extempore basis, notably hisfree fantasy interludes, the toccatas and the ruminative elaborated chord sequences in his preludes (BWV 921-923). In addition, many pieces may have originated, at least in part, as material for the exercise of Bach's own virtuosity. However, these virtuoso and improvisatory elements, the urge 'to run or leap up and down the instrument, to take both hands as full as all the five fingers will allow and to proceed in this wild manner till he by chance finds a resting place? represent only one side of the musical make-up of the young Bach. Just as strong, and eventually predominant, was the impulse to create order in sound, to excel in the art of musical construc-tion. Here Bach appears to have been very largely self-taught. His search for compositional models is illustrated in the story of his illicit copying during the Ohrdruf years (1695-1700) of a book of keyboard pieces belonging to his elder brother Johann Christoph. This book, which is no longer extant, contained music by three seventeenth-century South German composers (J. J. Froberger, J. C. Kerl and J. Pachelbel) two of whom (Kerl and Pachelbel) were linked with Johann Christoph in a direct teacher—pupil line.

The Prelude (Fantasia) in A Minor (BWV 922), is an extraordinary example of minimalism. Bach's seemingly endless variations on so simple a figure is a textbook case of harmonic development. Organists don't find this piece in their volumes of "Bach organ music" because of the artificial division that happened more than 100 years ago between Bach "organ" and "keyboard" pieces. The pedal part scored is at the player's initiative and discretion. In most of the ways that harpsichordists tune, the triads of B, F#, and C# majors sound rough ... and this piece uses enough of them to make it challenging.

Bach likely wrote this music in his late 20s. Some sections of the piece are long and repetitive, with little happening beyond some adventurous modulations (akin to those of the f# minor toccata, BWV 910). In the equal temperament of pianos and most organs, it is difficult to make much of this without being unimaginative. The piece is arguably too big and boisterous for the clavichord. Although mostly unplayed, it deserves better!

Source: Wikipedia (https://en.wikipedia.org/wiki/List_of_keyboard_and_lut e_compositions_by_Johann_Sebastian_Bach).

Although originally written for Harpsichord. I created this Arrangement of the Prelude (Fantasia) in A Minor (BWV 922) for Concert (Pedal) Harp.