Pitch Logic
The Pitch Logic card determines what notes play. It combines a scale selection system (150+ scales) with a pitch pattern algorithm (11 methods) that decides how pitches are chosen from the scale. All pitch patterns are streaming — they maintain internal state and produce the next pitch on demand.Pitch Pattern Algorithms
| Algorithm | What It Does |
|---|---|
| Sequential | All pitches in the set must sound before any can repeat (with octave displacement allowed). Ensures complete coverage of the pitch space within each cycle. |
| Spiral | Spirals outward from a center pitch, alternating above and below in expanding intervals. Creates a widening melodic cone. |
| Fibonacci | Next pitch determined by a growth-series interval sequence. Direction reverses when pitch boundaries are reached. |
| Register | Systematic traversal through octave registers — plays through one octave before moving to the next. The Order parameter shifts from sequential to shuffled traversal. |
| Probabilistic | Weighted probability transitions where closer intervals have higher probability. The Leap parameter shifts the bias from stepwise motion toward larger leaps. |
| Golden Ratio | Divides the pitch set at the golden ratio point, creating two subsets, and alternates between them. |
| Beating | Constructs a pitch set from the interference of two interval generators. Produces combination-tone-derived collections. |
| Mirror | Alternates between original pitches and their inversion around a configurable axis. Creates palindromic pitch contours. |
| Permutation | Systematic reordering of the pitch set through circular rotations, retrograde, and other transformations. |
| Corpus | Pitch transitions shaped by a learned transition model. The Context parameter biases toward ascending motion, stepwise motion, or large leaps. |
| Arpeggiator | Polyphonic arpeggiator across all active layers, locked to the current scale and root. The pattern parameter controls speed and direction. |
Parameters
| Parameter | Range | Default | Description |
|---|---|---|---|
| Pitch Selection | — | Sequential | Algorithm selection |
| Pitch Pattern Shape | 0.0–1.0 | 0.5 | Algorithm-specific control (see below) |
| Scale | 0–150 | C Major | Scale selection from library |
| Root Pitch Class | C–B | C | Root note |
| Starting Octave | −1 to 9 | 3 | Base octave for pitch set |
| Octave Span | 1–10 | 4 | Number of octaves to span |
| Custom Pitch Classes | bitmask | all on | Custom scale via 12-bit pitch-class mask |
Pattern Parameter Meanings
The Pitch Pattern Shape slider controls different aspects depending on the active algorithm:| Algorithm | What it controls |
|---|---|
| Sequential | Octave displacement spread |
| Spiral | Center pitch position |
| Fibonacci | Interval magnitude scaling |
| Register | Sequential ↔ shuffled traversal order |
| Probabilistic | Stepwise ↔ leaping bias |
| Golden Ratio | Split point adjustment |
| Beating | Generating interval adjustment |
| Mirror | Inversion axis position |
| Permutation | Transformation type |
| Corpus | Motion bias (ascending / stepwise / leaping) |
| Arpeggiator | Speed and direction |
Scale Library
RESERVOIR includes 150+ scales spanning:- Western modes — Major, Minor, Dorian, Phrygian, Lydian, Mixolydian, Locrian, Harmonic Minor, Melodic Minor
- Pentatonic and blues — Major Pentatonic, Minor Pentatonic, Blues
- Symmetric — Whole Tone, Chromatic, Diminished, Double Diminished
- Japanese — Kumoi, Iwato, Hon-Kumoi-Joshi, Banshiki-Cho, Naka Zora, Noh, Kokin-Choshi, Shimo-Chidori, and more
- Indian ragas — Yaman, Bhairavi, Todi, Marwa, Lalit, Hindole, Kafi, and more
- Synthetic and microtonal — quartal formations, mutated hexadic scales, intervallic mutations
- Ancient — Archaic Greek, Chinese Reform, Mongolian
- Custom — User-defined pitch class set via bitmask