Musical ideas from the F# minor prelude carry over into the F# minor fugue, most notably, the pervasive use of a descending fourth in the prelude which transforms into an ascending fourth in the fugue. Additionally, both pieces have similar rhymed, syncopated endings. Consequently, I consider them together as one larger work (as opposed to two unrelated pieces that happen to be in the same key or two pieces that are vaguely complementary).
Long, flowing, florid melodic lines are common in Baroque music. When learning this prelude, I found myself thinking about the particular challenges these long lines can pose for performers. Combined with another common characteristic of Baroque music — contrapuntal textures where each voice is about equally important — there is a danger of creating an impression that things are just dragging on. As one voice is wrapping up, another is just getting started, which makes phrasing difficult. (As an interesting aside, this particular challenge was mitigated in later music, with the popularization of more homophonic textures. A single melodic line with a corresponding accompaniment allows for very clear-cut phrasing, which many find easier to comprehend. It also enabled composers to create larger-scale works.)
Bach: Contrapuntal textures — here we have three equally important parts.
Mozart: Homophonic textures — here we have melody + accompaniment. We are more used to listening to this type of music.
To manage these lines, I found it useful to look for the slower melodic movements that are embedded within the overall structure (aka I engaged in a mini-Schenkerian analysis). Digging into the music, even just a little bit, can provide some insights for how to shape the melody and build up larger phrases. Here’s an example of how I thought about the F# minor prelude. This kind of thinking was also helpful for memorizing the piece. I kept the left hand’s part unchanged, and just focused on the slower melodic movement of the right hand, which usually had more to do.
The F# minor fugue is unusual — a lengthy triple fugue. It begins with a single voice providing the first subject which, when stripped down, is an upper neighbor gesture beginning on the dominant then proceeding down the scale to the tonic.
Look, I highlighted the important notes. Audio is below.
Almost immediately, we hear references back to the prelude in the accompanying countersubject. Rising fourths — a response to the falling fourths that featured prominently in the prelude — are noticeable within the first few phrases of the piece. The first exposition unfolds conventionally, with the gradual introduction of the three voices, a short episode to develop things along, and a restatement of the subject in the original key. However, this final restatement is subverted. It does not cadence on F# minor as one might expect, but rather in A major, the relative major.
At this juncture, the second subject enters, and we hear a very quick second exposition. The second subject is short: simply a descending scale with a dotted rhythm.
Introduction of the second subject: two measures. Boom. Done. Moving on.
Within the span of two measures, all three voices have been reintroduced and we can move right along. What follows is near constant restatements of this new subject, with some allusions back to the initial subject (most audibly with the quick sixteenth-note gesture). However, the voices I find most interesting are not the ones tasked with endlessly perpetuating the new thematic material, but rather the voices (usually soprano and bass) with a sequence of rising fourths.
Look at all the rising fourths. This isn’t even all of them.
From a musical standpoint, this gesture does a couple of things. Melodically, it provides a counterweight to the constant descending scalar patterns and moves us into a higher register on the keyboard, lending a hopeful quality to the music. Harmonically, it moves us through several different keys, which keeps things interesting. More than that, though, I just like how rising fourths sound, and I almost always chose to prioritize them whenever I encountered them (which was a lot).
After we hit our local high point — the sequence has risen as high as it can, and we’ve cadenced in F# Major (parallel major) — we hear the original subject in tandem with the second subject for the first time. This is a big event, and eventually leads us into C# minor (the dominant, we are making our way back to where we started). Here, we are introduced to yet another subject which begins in the alto, moves into the soprano, and then into the bass. Unlike the previous two subjects, this subject of running sixteenth notes does not get its own exposition, but is instead immediately integrated into the fugue’s existing material.
Compositionally, the rest of the fugue is pretty standard issue from here. All of the major musical material has been introduced. We hear various combinations of the three subjects, some lyrical episodic material, and eventually wrap up with a dramatic restatement of the original subject in the original key, F# minor.
From a performance standpoint, however, these last two pages are demanding. Once the third subject is introduced, there are constant running sixteenth notes for the rest of the piece. Learning how to keep these running lines even, shapely, and not incessant-sounding was difficult. Also, with so much going on, it can be difficult to process everything at a performance tempo — especially when playing from memory. There’s a certain balancing act between keeping track of every single note in every voice and (to some degree) letting muscle memory take the wheel.