Via Fafner's blog. As my hands continue to improve, I'm going back through emails and comments and having fun seeing what I've missed.
I never thought of Bach as a pedagogical designer before - it was always "just music" to me, and it wasn't until about 3 weeks ago while browsing through a music shop and reading the preface of a book of his 2 and 3 part inventions that I learned he actually designed some of his pieces to teach students things (...such as how to play pieces with multiple voices).
HOW DID I MISS THIS?
I think I'm going to appreciate playing piano pieces more now. It's this wonderfully monotonically increasing thing (monotonically increasing things* rock.)
*some of them, anyway. Stuff like "tumor size" or "number of civilians killed in conflict" are numbers I would rather keep at zero.