Guess what? Yep, another piano piece. While working on some of the string quartet stuff, I got to thinking about the previous four pieces and how they were all either slow or at most andante, and that I should do something a little peppier, or maybe just peppery.
Also, in #17, I had done something in creating the beginning part of the secondary theme that I thought might have more possibilities -- specifically, the use of increasing and decreasing intervals, which creates lines that are kind of like a cross between a scale run and an arpeggio; for example, C-D-F-Bb-F or C-G-C-Eb-F (the E needn't be flat). That's with them all going in the same direction; you can also alternate directions, getting something that turns in on itself: C-G-D-F#-E (and the F needn't be sharp). You can append one instance at the end of another, and so forth. And that's how I got this.
There are lots of fast runs in this, but along with the fireworks are the occasional slow passages, just to be able to catch your breath. A lot more chromaticism with this one, although it's more or less centered on A, but not really major or minor (the final chord contains 4 A's, a D and an E, just to avoid making it either). And, being as fast as it is, it's also rather short, just about two and a half minutes, in order to spare both the fingers and the ears. Needless to say, this one's even less like a waltz than #15 (the one that I explicitly declared to be not a waltz), so there's no need to mention it.