The Sound Cells series did not begin as a publishing project. It began as a compositional practice — Bruce Arnold writing pieces using pitch class set trichord pairs, starting with the hexatonic system he had developed from his studies with Charlie Banacos and Jerry Bergonzi, beginning in 1990. The idea of organizing those compositions into a systematic series, with exercises, scores, audio files, and pedagogical text, came later. Much later.

The journey from the first compositions to the 78-volume published series spans 35 years and every major change in music production technology — from hand-entered Finale scores on early Macintoshes, through MIDI sequencers and CD-ROM distribution, to AI-assisted content generation, cloud storage, and web-based streaming. Understanding this journey illuminates both the history of music technology and the specific choices that shaped the Sound Cells series into what it is today.

The Timeline

The Technology Transition at Each Stage

Each major technology transition in the pipeline brought not just efficiency gains but qualitative changes in what was possible:

What “Systematic” Required

The shift from “compositions in a trichord pair system” to “78 volumes systematically covering all trichord pairs” required something that no compositional practice can provide: completeness. A composer writes pieces they find interesting. A systematic series requires that every trichord pair be covered, every transposition documented, every exercise format produced — regardless of whether any particular combination is especially interesting to the composer in that moment.

This is where computation became essential. The LilyPond and SuperCollider pipeline could generate exercises for trichord pairs that Arnold had never specifically composed in — not because those exercises were less valuable, but because the system’s completeness required them. The exercises for the 012-048 trichord pair (chromatic cluster plus augmented triad) may not represent a combination Arnold would naturally gravitate toward in his own composition. The system covers it anyway, because a complete map of the hexatonic space covers all 78 unique pairs.

The Role of the Compositions

While the exercises could be generated, the compositions could not. The 149 original compositions spread across the 78 volumes — from early pieces like Give ’em Some and Dakota Gumbo (013-013) to the fine structure constant pieces (026-026) to the Great Houdini blues catalog (025-025) — represent 35 years of actual creative engagement with each trichord pair. They cannot be computed. They must be composed.

This is the irreducible human contribution to the Sound Cells series: not the exercises, not the scores, not the metadata (all of which can be generated), but the compositions that demonstrate what each trichord pair actually sounds like in the hands of a musician who has lived with it for decades. The computer generates the map; the compositions are the territory.

The STEAM Articles — Discoverability as Engineering

The articles you have been reading — this series on hexatonics and the STEAM disciplines — are themselves part of the engineering stack. The Sound Cells series exists and is accessible. What it lacks is discoverability: the ability to be found by students, educators, and curious people who don’t already know to look for it.

These articles solve that problem by creating content that explains the mathematics, physics, neuroscience, and engineering of the hexatonic trichord pair approach in language that reaches students from STEM backgrounds — people who will encounter these articles not because they are looking for music theory but because they are looking for the fine structure constant, or set theory, or harmonic series, or SuperCollider, or Cloudflare R2. When those searches lead to these articles, and those articles lead to the compositions and courses, the engineering of discoverability has worked.

This is the final stage of the journey from Finale to the web: not just making the music accessible, but making it findable.