What imparts a feeling of forward momentum to the subject in Bach's Fugue in G Minor?

In Bach's Fugue in G Minor, the feeling of forward momentum is primarily imparted by the technique of using shorter note values as the piece progresses. This approach creates a sense of acceleration and urgency, allowing the music to build energy as it unfolds. As the note values decrease, the rhythm becomes busier and more vibrant, enhancing the dynamic forward drive of the composition.

This progressive shortening of note values helps to engage listeners, pulling them deeper into the intricate counterpoint characteristic of Bach's fugal writing. In contrast, factors such as changes in tempo, modulation to different keys, or variations in volume do not necessarily create the same direct sensation of forward movement as the rhythmic intensity generated by the shortening note values. Thus, the structure of the fugue and the way it evolves make the shortening of note values a key element in creating a compelling sense of movement.