The "Aria with various changes for harpsichord" received its common title "Goldberg Variations" according to Johann Nikolaus Forkel, who relied on reports from the older Bach sons. This was because it was a commissioned work from the Russian envoy at the Dresden court for his house harpsichordist, Johann Gottlieb Goldberg. However, this account has often been contested, as Goldberg, who became a student of J.S. Bach around 1737, was only 12 or 13 years old at the presumed time of the work's creation (around 1740). Nevertheless, the highly talented Goldberg likely played the exceptionally demanding variations frequently. Difficulty level: 5.