Fourth Movement: Allegro 3/4 B minor

A rondo form significantly shortened from the initial draft. Although the sustained B note at the beginning guarantees the tonic key, the theme's opening with an added-sixth chord and the repetition of the leading-tone progression eis→fis in the dominant key create a sense of unease for the listener. Upon entering the theme's restatement without a definitive tonic chord resolution, the modulation process begins with a shift to G major in the post-thematic phrase.

The couplet (from m. 64) contrasts with the rondo theme in its opening in the relative major, the piano's melodic voice, and its vibrant accompaniment. In the latter half, into the seamless flow of music, which gains momentum through the urgency of the motives, accented augmented fourths and chromatic bass lines intervene, transitioning into a harmonically unstable phase.

The second rondo theme is varied from the outset in both timbre and structure, featuring a piano melody and responsive accompaniment figures between instruments. The theme's restatement is limited to the preceding phrase, and from m. 137, it becomes a site for motivic development centered on the opening and closing motives of the rondo theme.

Following transitional material, the couplet reappears from m. 205 in B major. Subsequently, the seventh of a diminished seventh chord at the end of the episode serves as a link to the next section. Here, piano arpeggios present diminished seventh chords and ninth chords on the tonic or dominant, sustaining harmonic tension.

From m. 266, strings and piano engage in a powerful chordal dialogue with clear B minor harmonic progression. Here, a tonic resolution is avoided, and the subsequent theme restatement begins in E minor. This is a skillful measure. Because the original form of the theme includes a leading-tone progression in the dominant key, starting in the subdominant key ensures that the tonic key is emphasized in the final presentation of the theme.

However, true stability in the tonic key remains distant, and even in the coda, the key still floats among related keys. Towards the end of the coda, the thematic motive continues, ascending in pitch, and upon entering the tonic perfect cadence, it further fragments and intensifies, leading the music to its final climax. The piece concludes with a three-measure tonic chord.