This Bach fugue has always been one of my favorite to play. Not just because it’s loaded up with 5 voices (instead of the more common 3- and 4-voice fugues), but because of its simplicity and absolute genius.

Before I get into the nitty-gritty details of the piece, I want to quickly explain what fugues actually are.  Formally speaking, fugues are a very systematized and logical way to combine multiple voices that are built on a single principle theme, or what we call subjects.

Informally speaking, picture yourself singing with 3 other professional singers.  All is silent, and then you decide to sing a simple melody by yourself. This simple melody that you sing is what we will call the subject.  The next singer listens to what you have to say and then sings the subject, but maybe in a different key. Now there are two of you singing at the same time. The 3rd singer now comes in, sings the subject, maybe in a different register, and has to alter it slightly to that it harmonizes well with you and the 2nd singer. Now there’s 3 of you singing. Finally, the 4th singer comes in. Again she is required to sing the subject, but probably has to do it in a different way so that it sounds good with the rest of the bunch. Now we have you and all of your singer friends all singing at the same time, and singing notes that are very strictly related to the original melody (subject) that you first created. Sounds fun, doesn’t it?

That’s a pretty silly and unrealistic example, but is the general thought process for anyone who has the nerve to write a fugue.  Baroque composers, who lived in an age of science and systematic process, really perfected the technique.  J.S. Bach, in my opinion, was the best and most prolific. Especially when it comes to fugues written for the keyboard.

So now, back to his fugue written in b-flat minor, BWV 867 from the first book his super famous collection of preludes and fugues, The Well-Tempered Clavier.

The subject of the fugue is shown below:

The second voice then comes in “singing” the subject using the same rhythmic pattern, but on different notes (transposed down a 4th).

The two voices sing together for a while, then the third comes in, singing the subject exactly like the first, but an octave lower (notice the bass clef):

Next, you guessed it: the fourth voice comes in. Here it is lower than the 3rd, playing the same notes as the second voice, but an octave lower. Also notice the A natural Bach threw in there to accommodate the harmonic changes.

So now, we have 4 voices all singing at once. But we have one more to go. The 5th voice is added singing deep in the bass register, and singing the exact subject except for a D natural at the end:

So as you can see, the voices are added sequentially, and very systematically. It can get very complex, but this simple subject allows the listener to follow the music without getting bogged down too much.

Give this fugue, or any fugue for that matter, a few good listens before judging it or deciding to play it. Fugues can be somewhat complicated and “thick”. I like to think of fugues a s a sort of chase game where the subject is being chased from one voice to another. When we listen to fugues, we follow that chase. The subject stays the same, but takes on endless new shadings  as it turns corners and surrounds itself with different melodic, harmonic, and even rhythmic ideas.

Here’s a great video I found that illustrates this fugue in a very clean format. Normally Bach’s fugues are written on two staves. This video puts each voice on its own staff, so that you can follow each one much more easily.

Also, here’s a link to a .pdf of the prelude (which is also wonderful) and fugue (starts on page 3).

That’s it for now. Please continue to send me more questions or comments! I really love talking about and discussing this wonderful music!