A study piece from 1821, when Mendelssohn was 12 years old. The first edition was published posthumously in 1868. The opus numbers were assigned by publishers and editors after Mendelssohn's death, and therefore do not correspond to the order of composition.

A three-movement sonata, with a fast-slow-fast structure.

First Movement: G minor, Allegro

Characterized by the use of the same motif in both the first subject in G minor and the second subject in B-flat major. This use of a monothematic sonata form is influenced by Haydn. These short motifs reappear throughout the movement in various guises.

Second Movement: E-flat major, Adagio

Marked Cantabile e lento, the melody unfolds very gently. It would be beneficial to perform this movement while perceiving the changing harmonic colors in each section.

Third Movement: G minor, Presto

Over a simple rhythmic accompaniment supported by functional harmony, the right hand frequently employs scalar passages. A sonata form with a short development section.