Noctave
The piece
A Polish dance in triple time, the polonaise is recognisable by its first beats cut into short values: an eighth followed by two sixteenths, or a dotted eighth and a sixteenth. Nobody knows who wrote this G minor piece, listed in the appendix of the BWV catalogue. Its second part moves to B-flat major, then heads back toward the minor through cadences on D.
That characteristic rhythm is the first thing to secure: the eighth followed by two sixteenths must not turn into a triplet. Count in sixteenths at first, under your breath. The sixteenth-note runs in the second part, where the right hand peaks at just over four notes per second, need a fingering settled once and for all. The left hand walks mostly in quarter notes, sometimes in eighths that answer the right: keep it steady, since it sets the step of the dance. The E-natural and F-sharp that often appear in the left hand are worth spotting before you play.