While the Prelude is nominally written strictly in 4/4 time, there are passages where it is unclear whether they are 16th notes or triplets. Since improvisation is fundamentally required, please consider the bar lines as virtually non-existent. There is no particular need to feel the 4/4 time signature when playing.

As for the Allegro, the theme appears in various keys:

• m. 1: A minor
• m. 14: E minor
• m. 29: C major
• m. 33: D minor
• m. 48: A minor

What lies between these sections are mostly harmonic sequences. From the author's perspective, C major may be played with a soft tone. For the subsequent E minor and D minor sections, please play with the tone quality and volume that the performer feels appropriate. The tension might be higher than in the original A minor.

The theme is to be regarded as four measures long. For example, in measures 1-4, the theme extends up to G# on the first beat of measure 4. During this, increase the volume from measure 1 to measure 2, and from measure 2 to measure 3. With the first beat of measure 3 as the peak point, create a shape that descends from there to reach measure 4. Please apply similar shaping to other themes as well.