IV. Largo - Fuga (第四乐章 广板 - 赋格)-Jean-Bernard Pommier

The movement begins with a slow introduction that serves to transition from the third movement. To do so, it modulates from D♭ major/B♭ minor to G♭ major/E♭ minor to B major/G♯ minor to A major, which modulates to B♭ major for the fugue. Dominated by falling thirds in the bass line, the music three times pauses on a pedal and engages in speculative contrapuntal experimentation, in a manner foreshadowing the quotations from the first three movements of the Ninth Symphony in the opening of the fourth movement of that work. After a final modulation to B♭ major, the main substance of the movement appears: a titanic three-voice fugue in 3 4 meter. The subject of the fugue can be divided itself into three parts: a tenth leap followed by a trill to the tonic; a 7-note scale figure repeated descending by a third; and a tail semiquaver passage marked by many chromatic passing tones, whose development becomes the main source for the movement's unique dissonance. Marked con alcune licenze ("with some licenses"), the fugue, one of Beethoven's greatest contrapuntal achievements, as well as making incredible demands on the performer, moves through a number of contrasting sections and includes a number of "learned" contrapuntal devices, often, and significantly, wielded with a dramatic fury and dissonance inimical to their conservative and academic associations. Some examples: augmentation of the fugue theme and countersubject in a sforzando marcato at bars 96–117, the massive stretto of the tenth leap and trill which follows, a contemplative episode beginning at bar 152 featuring the subject in retrograde, leading to an exploration of the theme in inversion at bar 209.