K. 61

Gilbert Edition: No tempo marking, 2/4, A minor, 3:20

The only set of variations among the 555 sonatas. It consists of a theme and 12 variations, with the theme being varied through arpeggios, rhythmic alterations, and other techniques. (The 12th variation serves as a coda. While it deviates significantly from the theme in both phrase structure and melodic line, there are correspondences with the theme in its cadences and melodic contours.) Regarding its form, it is noteworthy that while the initial theme phrase is 6 + 6 = 12 measures long, from the 5th variation onwards, the phrase length of each variation is shortened to 5 + 5 = 10 measures. Although this includes a change in the phrase structure itself, the motive at the cadence of each half-phrase is maintained throughout the entire piece, albeit partially, without significant alteration. This strongly contributes to the overall unity and the sense of correspondence between the variations. Furthermore, from the 7th variation onwards, the characteristic dotted rhythm of the theme reappears in the bass at the beginning of each phrase, in the form of a quarter note and an eighth note separated by a rest. As a result, the entire work is effectively divided into two halves by the difference in the basic rhythm of the bass at the beginning of the phrases.