This is a fugue of great tension. One reason for this is that the theme (subject) ascends stepwise, creating a sense of being gradually moved to higher places with each slow ascent. Since this is fundamentally a three-voice fugue, octave progressions, such as that in measure 53, should be considered as a single voice rather than parallel octaves.

In this fugue, to emphasize the theme, it is written in octaves or, as in measure 109, in weighty chords. It is reasonable to assume that the volume increases with the number of notes.

When considered in this light, such octave or chordal themes do not appear until measure 53 in the first half. Octave and chordal themes appear more frequently in the latter half.

Therefore, it is appropriate to consider the overall flow of this fugue as progressing from pp to ff, starting pp and gradually increasing in volume until reaching the final theme in measure 136.

From measure 136 onwards, a slight reduction in tempo to emphasize the gravitas would be appropriate.