2025-05-30

tonal

cyclic, bounded pitch structures-finite sets with internal order, repetition, or symmetry, regardless of musical tradition.

introduction

the tonal domain belongs to the pitch layer and generates static pitch sets: finite, repeatable pitch structures used as sources for melodic, harmonic, or pattern-based material. unlike atonal (which emphasizes chromatic grids or unordered sets) or generative (which evolves over time), tonal defines closed, internally constrained pitch behaviors. these forms are abstract, deterministic, and culturally neutral-capable of expressing traditional modes or entirely novel configurations with equal ease.

overview

each form produces a cyclic or bounded pitch map, accessed by an index:

0. ring_scale

behavior: circular scale of n degrees repeating every m* semitones analogy:* generalized diatonic or synthetic mode parameters:*

  • a: number of degrees per cycle (3 to 12)
  • b: total span in semitones (6 to 24)

1. symmetry_set

behavior:* builds sets with reflective or rotational symmetry around a central pitch analogy:* scale as a geometric object (e.g. palindromic, radial) parameters:*

  • a: symmetry type (mirror, radial, rotational)
  • b: span or folding depth (center outwards)

2. grid_arpeggio

behavior: traverses an n*-dimensional pitch grid along a structured path analogy:* arpeggiating chords across pitch planes (e.g. stack + rotate) parameters:*

  • a: grid axis ratio (e.g. 3:2, 4:3)
  • b: traversal path type (linear, zigzag, spiral)

3. loop_melody

behavior:* cycles through a fixed, user-defined pitch sequence with controllable loop offset analogy:* a sequencer rotating through a melodic cell parameters:*

  • a: loop phase offset (0 to sequence length)
  • b: pitch bend or variation depth (±3 semitones)

parameter behavior summary

ring_scale*

  • a: number of scale degrees (step count)
  • b: total interval span (defines coarseness) symmetry_set*
  • a: symmetry structure (mirror vs. radial fold)
  • b: how deep or wide the symmetry reaches grid_arpeggio*
  • a: grid shape (intervallic ratio between axes)
  • b: traversal path shape over the grid loop_melody*
  • a: sequence index offset (wraps)
  • b: per-step transposition or contour modulation

why these were chosen

generalization over tradition: instead of encoding specific modes or chords, these forms define general structural constraints* (cycle, symmetry, grid, loop) that include traditional scales as special cases. structural integrity:* each form expresses a unique way to constrain or repeat pitch space, irreducible to others. two-parameter sufficiency:* all behavior is navigable with just a and b, preserving the system's parametric purity. cultural neutrality:* avoids style-imposed assumptions-usable for both familiar and entirely synthetic pitch designs.

what is not included

chromatic/microtonal collections:* handled in atonal. evolving or probabilistic materials:* belong to generative. tuning/frequency assignment:* deferred to tuning. user-defined note names or keys:* not part of pitch logic-these are display-level concerns.

conclusion

the tonal domain defines compact, cyclic pitch sets through structural primitives-cycles, symmetries, grids, and sequences. its forms serve as deterministic sources for both familiar tonal contexts and non-traditional pitch materials, supporting the project's goal of generating all structured sound, not mimicking any particular musical idiom.