Bach, Well Tempered Clavier, Fugue No 4 in c# minor

What's neat about this fugue is that it's subject is simple and short, the notes are slow and long like a lament--do ti me re--so it's symmetrical in the sense that you have a half step down and then another half step down at a different interval, plus the two outer notes begin as whole notes while the two inner notes are half notes. Neater still, is that you can break the subject down into really just a repeated half step transposed. So simple. Yet...yet...it's that Bach takes this little thing and makes the fugue so complicated, running beneath it scores and scores of eigth notes--and he uses a total of four voices, but sometimes the fourth drops out. Those intervals, the minor second and the tritone, so poignant. But I love polyphony and minor modes.