This fantastically entertaining chestnut has been keeping me happily occupied for the last month or so after I enjoyed a friend's very capable study of it. Chopin wrote four wildly popular scherzos, and this particular piece is precariously perched on a narrow margin between popularity and triteness. It remains however clear that this work has more than enough thematic and motivic substance to back up its popularity -- to say nothing of sheer beauty -- and luckily there has been extensive analysis and commentary already written... which I have not had the opportunity to read. Let's reinvent the wheel then, shall we?
It's roughly in an embellished ternary form with a coda, resembling AABCAD: C is a romping and dramatic series of variations of previous themes in various keys, and D is a rapid and virtuosic coda, showcasing a rich harmonic vocabulary and a taste for showmanship. Each the A section and B section contain distinct sections as well.
There are many YouTube recordings of this particular marvel, but among the best is Zimerman:
In this recording, B (sostenuto) begins at 3:33, C begins with a furious diminished arpeggiation at 7:05 (and includes at 7:49 the first return to Bb minor since the opening of the piece!). The recapitulation of A begins at 8:26, and rips into the final coda at 9:57.
More thoughts on meaning and phrasing to follow.