In 1802, Johann Nikolaus Forkel, Bach's first biographer, related the legend of the origin of the Goldberg Variations, thus contributing considerably to the work's fame. They were allegedly the object of a commission from Count Kayserling, former ambassador of Russia to the court of the Elector of Saxony. The Count, suffering from insomnia, had a former student of Bach's in his service, the young Johann Gottlieb Goldberg, who played the harpsichord to divert him during his sleepless nights. He never wearied of hearing 'his' variations that, according to the story, were composed in exchange for a golden goblet filled with gold coins. Forkel's account is pure fiction. Contrary to custom, Bach left no dedication on the frontispiece of the edition. In addition, it is unlikely that Goldberg, aged 14 at the time, could have performed such a difficult work! Finally, although the coins could have been spent, there is no trace to be found of the golden goblet in the inventory of the composer's belongings drawn up after his death. However, the Goldberg Variations bear witness to the Cantor of Leipzig's genius, then at its peak, combining peerless performing feats and the unequalled art of a refined, scholarly composition.
These variations for harpsichord occupy an exceptional place in Bach's catalogue, constituting, in a sense, the fourth part of the Clavier Übung and opening the way for the great speculative works: the Musical Offering, Canonic Variations and Art of Fugue. In his important study devoted to Bach, musicologist Alberto Basso places this composition of 1741 midway between musical practice and theoretical music, describing it as Ars Artificialis. This aria and its thirty variations put the finishing touches to Bach's experimenting at the keyboard, exploiting the variation form to the exhaustion of the theme.