OK, so as I wrote in the Title Explanation, this single composition is a conflation of three different piece ideas. The [Ar]4s¹21d¹ portion of the title indicates that the piece will be programmatically concerned with the collision of classical and quantum physics (hence all that crap about subatomic particles in the titles and score). There are more details about this on the page about the Rydberg series, but for this piece classical physics is generally represented by dispassionate presentations of tone-row melodies while quantum ideas are represented by aleatoric blasts of cluster harmonies.

the p/-\!1mps3$t ε component of the title indicates that the piece is in two movements; the first concerned primarily with cuts and juxtapositions while the second features more gradual combinations of musical ideas. To be honest this particular second movement is not so representative, but you will hear ostensible "classical physics" 12-tone melodies that are gradually effaced by clustery glissandoes and detunings reminiscent of the "quantum" sounds elsewhere in the movement.

Finally, the brokenAphorisms_19&20 part of the title indicates that these two Palimpsest movements are also two brokenAphorisms, and as such are rendered using a visual score. If you look at that PDF, you'll see that the first (largely "classical") movement is organized in the shape of an atom as they were once thought to look. This Bohr-model—wherein electrons orbit a nucleus of protons and neutrons like planets around the sun—is now known to be false except in very specific circumstances (such as Hydrogen atoms and the elusive Rydberg atoms that inspired this piece). The second movement illustrates its more quantum outlook with a couple of sections organized in the shape of Feynman diagrams, a visual system developed by Richard Feynman to illustrate the complex interactions of subatomic particles and virtual particles. For example, the first visual part of the second movement is modeled on this diagram:

OK, OK, enough! Let's talk about the damn music!

And but so anyway, the first movement alternates between two types of music. The first involves unorganized clusters, wherein all four instruments freely play notes in the "nucleus" of the score (sometimes in normal tuning, represented by open notehead "protons"; sometimes detuned, represented by filled notehead "neutrons"). The second musical type involves rigidly organized sections where the instruments intone rhythmically simple melody lines using the prime and inverted forms of a 12-tone row. These last are represented in the score by the three different speed ("energy-level") orbits around the nucleus. In the end, the four instruments move around and through these orbits, creating overlapping presentations of the rows until the abrupt and angry conclusion.

The second movement has a far more impetuous—almost improvisatory—sound, which is appropriate for a movement that deals with the strange and unpredictable interactions of quantum particles. After an inchoate introduction (using the aleatoric rhythmic pattern I refer to as "brain zaps"), the first Feynman diagram is performed. The trumpets play the role of a colliding electron-positron pair. As in the first movement, the electron is represented by P and I row forms. The positron, which is the anti-matter counterpart to the electron, is represented by the same row, but in Retrograde (or Retrograde-Inversion) forms. This echoes the strange, but scientifically sound, fact that positrons are indistinguishable from electrons that are moving backward in time.

The two trumpets collide on the same final note, initiating the trombone's entrance, which involves slow glissandoes, intended to represent the wavy lines used to represent photons. The trumpets reënter with another simultaneous row presentation (the circle in the middle of this part of the score). They play the same notes, but the first trumpet starts on the left side and moves clockwise around the circle, while the second starts on the right and moves counter-clockwise.

Wait, this is just supposed to be an Overview and I'm rambling on about every damn detail. Anyway, after another angry cluster section, the second Feynman part arrives. Two more row presentations ensue, but they are increasingly muddied by detuning and trombone (photon) glissandoes, reflecting the slow invasion of straightforward melody by clusters and rhythmic ambiguity. This is the musical "infection" referred to above as being characteristic of second movement Palimpsest forms.

*Whew*. There is no way anyone is reading this whole thing, right? Seriously, if this makes no sense, or is totally uninteresting or incoherent, just ignore it. Don't blame the piece for my nerdiness, it's got some really nice moments of both prettiness and nastiness.