Like a map of music - a quick guide to Bach fugues

This is a bit of a 'throw away' repost, but I hope some folks enjoy.

Bach was a genius. The perfect fusion of math and logic with creativity and emotion.

Especially his fugues. And this fugue SLAPS.

A fugue is a form of writing with some specific rules. Below is a video for his Little Fugue in gm. It's a fairly simple, straight forward fugue and the video is strongly visual so even if you can't read music you can easily follow along. 

Just a tip or two about listening to baroque counterpoint:

Most music we listen to is 'vertical'. You have a fairly strong melody and it is supported with chords. Your ear focuses on the melody and the chords give strength, color, texture, or whatever.

For western music before the classical era, think more horizontally. Chords aren't really a 'thing'. It's not that they didn't use chords, it's more that the focus is on several melodies supporting each other. They intertwine. It's listening to several melodies playing at once, and the harmony, color, texture etc is implied through how the melodies move against one another.

For a fugue, I'm not going into great detail, but BASICALLY you have one voice playing the 'motif' (a melody that is a few bars long, usually what we might call a 'hook'). This is called the 'subject'. 

The next voice comes in playing the melody again, but starting at a different pitch (usually the dominant pitch for the techy music geeky types) The new voice is not a different key, so the melody is slightly altered to maintain the key. The first voice plays a new section called the 'counter subject' and they intertwine with each other.

Third voice will come in on the original pitch, but in a different octave. Voice two picks up the counter subject, and the first voice either does a second counter subject, or free material.

Once all of the voices enter (and there can be any number of voices from two to a dozen or so), each one alternating between tonic and dominant, this 'exposition' section ends, and the 'development' section begins by 'playing with' the motifs and counter subjects, and free material. The voices will reenter from different pitches, there may be key changes, implied additional voices, the motif might be played with double note values, halved note values, or upside down, or backwards, and the same with the counter subjects. There a lot more rules for polyphonic writing, but this is already too long.

About THIS fugue. This is a fugue in G minor with four voices. Just under four minutes, and the visuals really highlight how the motif enters and is played with. Enjoy this one! It is a FANTASTIC piece of music, yet fairly straightforward for a Bach fugue!