While being in a position to possibly finish the previously threatened Perenepsis #5 before #4, something else popped into my head two days ago and is already done. It's just a quick little thing, based on the harmonic series (hence the title), but I kind of like it. In contrast to the Perenepsis pieces, this is blatantly tonal -- E-flat major, chosen in order to render it more calm than bright -- with very few accidentals.
There is some interesting (to me, at least) stuff going on structurally beneath the "severely tonal" harmonic language. Overall, the form is ABA, with the B section (in 3/4) itself an ABA form, and the 4/4 A section breaks into ABC, and then CBA on the return. Breaking it down further, the 'A' part of the overall A is itself AABB, and BBAA in the repeat (and a slight overlap in the B's), with a V-I cadence sandwiched between the very last A's of the A part of the overall A section. Also, the 'A' of the overall B section is related to the 'B' of the overall A, the swapping of the left and right hand parts in the latter being a larger-scale version of the alternations in the former. I hope I can follow this a few months from now when I read it...
Mainly, though, it's just a nice, relaxing little thing that is considerably easier to play than my other recent works. My favorite part is the very last note; raising the G in the final chord by an octave really did something nice there: