Prelude

This prelude may appear simple at first glance, but it is written in a dense polyphony, occasionally transitioning abruptly into a four-voice texture. Therefore, it is a prelude that requires careful attention to its polyphony. Let's examine it from the beginning. In measure 1, the right-hand subject aims for E, then decays from E to reach B in measure 2. Thus, no accent should be placed on the first note, B, in measure 2. However, in measure 2, the soprano ascends to a high G# and descends to F##. No accent should be placed on this F##; play it softer than G#. The left hand in measure 1, however, merely starts an octave lower than the right hand. Therefore, the E on beat 2 is considered the apex, so the left hand should be louder on the downbeat of beat 2, while the right hand should be softer. Additionally, the left-hand D# on beat 2 is tied into the next measure, and measure 2 itself is already in a four-voice texture. As these examples show, pay meticulous attention to ensure each voice makes musical sense.

For patterns where notes are tied to the next beat or measure, such as the left hand in measure 1 or measure 3, be careful not to cut off the bass. In both measure 1 and measure 3, the left hand is in two voices, so treat both voices with care and avoid unnecessary breaks.

In measure 5, the eighth note on beat 1 in the left hand is a resolution from the previous measure; avoid placing an accent on it. Since this section modulates to B major, a softer sound would be appropriate. However, it quickly modulates to C# minor, reaching a climax in measure 9, where the harmony is a diminished seventh chord. Increase the tension here. Subsequently, it descends through a sequence, arriving at D# minor in measure 14.

From here, gradually build a crescendo towards measure 18, which is the climactic point of this prelude.

Incidentally, there are places that even professional pianists overlook. These are the two dotted quarter notes in the bass in measure 15. For some reason, these are often cut off in many performances. Connect them to the next note without creating a rest.

In measure 24, the repeated eighth notes in the right hand tend to become rough (due to being cut off), so connect them smoothly with the pedal. In measure 26, slightly slow down from beat 2, taking ample time to enter measure 27. At that point, the right-hand G# that is reached is normally a resolution, so it wouldn't be played loudly. However, this G# in measure 27 is tied and sustained for three measures, including a fermata. Therefore, it needs to be played slightly louder.

Fugue

Let the theme be from measure 1 to the first note, D#, in measure 3. While there may be various opinions, the articulation of the theme should generally be legato, with staccato applied to the two pairs of identical notes in measure 2, between beats 3 and 4. Of course, semi-staccato is also acceptable. However, for instance, if we assume that in measure 4, the right-hand alto is staccato while the two eighth notes in the left hand are sustained for their full eighth-note value, even though both hands play eighth notes, if one is played shorter and the other for its full value, the voices sound more independent. In essence, by playing two different musical materials with as distinct articulations as possible, you can make the voices sound independent. There is only one place in the piece where this articulation is almost impossible: the eighth notes in the tenor in measure 18, between beats 3 and 4. Due to the interplay with other voices, one is forced to use the pedal here, consequently losing the staccato, but this is acceptable.

Furthermore, there is one section where bringing out the theme is particularly challenging. This is the tenor theme starting from beat 2 of measure 32. As other voices are quite intertwined, it becomes difficult to make this theme clearly audible, but please practice with the theme in mind.

Measure 41 is the final measure, and some editions end with a minor third chord, while others end with a major third chord (Picardy third). For your reference, the Henle edition ends with a Picardy third.