Today’s post is the welcome B major P&F no. 23 after yesterday’s slog through no. 22. The delightful and easily understandable Prelude is followed by the fugue’s wild subject — the craziest I can recall JSB writing. It seems he was investigating the limits of a fugue’s subject for development. This subject, marked in the score above, stretches an octave, outlines an unusually complex harmony, and bounces within the octave like a hyper two-year-old. The result is that when new statements of the subject come up against countersubjects, they cross each other repeatedly, and before the fourth voice is introduced you already have a real puzzle on your hands. Which note goes with which line? What happened to the subject? And which note am I supposed to be holding for a duration? Reading through this will keep your mind off the unpleasant subjects which seem to fill the corners of modern life; mastering it would be a serious task.