Function

Builds the initial composition parameters (theta) for a list of steps by calling schema() on each.

Test:

• buildParameters
• buildParameters extracts flat parameter defaults for scalars and checkboxes
• buildParameters resolves nested defaults across same-step and cross-step counters; falls back when max is missing or counters are unresolvable

Creates the chord digraph G = (V, E, w) for a given mode, optionally tuned by a corpus preset (pi).

Test:

• chordGraph
• chordGraph provides major and minor defaults with nodes, tonic, cadence-normal-NC-loop cost ordering and edges aligned with costs.keys()
• chordGraph adds chromatic nodes from a preset, applies preset costs, clamps self-loops and skips unknown edges

Roman-numeral display: with keyIndex returns the concrete chord name; without keyIndex returns the function-label form for UI dropdowns.

Example:

chordName("I");       // "I: Tonic"  (label form, key-independent)
chordName("V", 0);    // "G"         (dominant in C major)
chordName("vi", 0);   // "Am"        (minor from lowercase numeral)
chordName("viio", 0); // "Bo"        (diminished from "o" suffix)
chordName("NC", 0);   // "NC"

Test:

• chordName
• chordName returns label form without keyIndex; transposes to concrete chord with sharp/flat spelling and quality suffix; passes NC and unknowns through

Run the 3-step composition pipeline (form, chords, notes); pure orchestration via hooks. Step 2 + Step 3 results are cached by part label so repeated labels (e.g. A in A-B-A-C-A) solve each unique label only once. View layer assembles the display table from labelCache. Implements roughly the Thesis' Algorithm.

Emit:

Test:

• compose
• compose returns null on empty input; emits MIDI + parts + solved cache + progression lines on the multi-label happy path; reports failed labels on partial fail; reuses Step2 + Step3 once for repeated labels via the label cache; falls back when step.solve returns null

Triggers a browser file download from a Blob or a Base64-encoded string.

Example:

downloadBlob(blob);                  // "2026-05-09T14-23-07" (default UTC timestamp)
downloadBlob(b64String, "song.mid"); // "song" (custom filename, returns stem)

Test:

• downloadBlob
• downloadBlob triggers an anchor download with stem return; accepts a direct Blob or decodes Base64 to audio/midi with a default UTC-timestamp filename

Exports the composition parameters (theta) as a JSON file download.

Test:

• exportParameters
• exportParameters serializes theta as JSON blob with parameters.json filename

Builds MIDI from part notes solutions N (N=1 for per-part preview, N=|parts| for full piece). Per-part time-signature and key/mode changes are emitted as mid-track meta events, so a multi-section piece (e.g. C major 4/4 -> A minor 3/4) renders with correct meta events at every part boundary.

Test:

• generateMidi
• integration: midi-writer-js emits a real MIDI binary with the expected header from a realistic solution
• integration: midi-writer-js produces one MTrk per voice in the combined file when multiple voices are present
• generateMidi emits per-voice tracks with header meta and one NoteEvent per sub-beat for a 2-voice 2-sub-beat input
• generateMidi extends preceding note via ties as a single T384 event and emits Cm key signature in minor mode; accumulates rests and orphan-ties as wait T256
• generateMidi returns null on empty parts input such as when all step-3 parts are UNSAT
• generateMidi emits TimeSig and KeySig at every multi-part boundary; scans ties across boundaries so held notes extend and meta events flush after

Reads a parameter JSON file and returns the parsed content. Restores composition parameters (theta) from a previously exported JSON file.

Throw:

Test:

• importParameters
• importParameters parses JSON; rejects on invalid JSON or FileReader error

Initialize the MiniZinc WASM engine; must run before any solveModel() call.

Test:

• initSolvers
• initSolvers calls init then returns the available solvers

Builds the MiniZinc COP for Step 2: shortest path of fixed length over the chord graph. MZN nodes are 1-indexed: solver path int i refers to graph.nodes[i-1].

Test:

• modelChords
• modelChords emits a structurally complete MZN with F4, H20 and cost_matrix; falls back to the graph tonic on opposite-mode tonic input
• modelChords emits cost_matrix when creativity > 0; grows n_nodes when a preset adds chromatic nodes

Builds the MiniZinc CSP for Step 3: assigns one note per active sub-beat and voice. Encodes T1-T3, R4, R9, H12, H19, M1, M9, M14 from the Thesis.

Test:

• modelNotes
• modelNotes emits a well-formed CSP with include, var declarations and solve satisfy and no minimize
• modelNotes supports scale, chord, atonal and minor pitch domains
• modelNotes emits bare constraints without sentinels when rest_pct = 0; emits holds and rests budget with sentinel-guarded H12, H19, M1 and M9 when rest_pct > 0
• modelNotes emits cross-voice inequality and parallel-fifth and parallel-octave constraints when H12 and M14 toggles are active
• modelNotes emits H19 interval constraints across phi thresholds at <= 0.2, mid and >= 0.8; skips them at neutral 0.5
• modelNotes emits xi seeding with max_interval, anti-osc and empty-cs branches; covers filterByDissonance variants

Chromatic note-name array (12 entries starting from C); flat-preferring by default (also used as MIDI key-signature labels), sharp-preferring when keyIndex (kappa) is a sharp-favouring key.

Example:

noteNames();    // ["C", "Db", "D", "Eb", ...] flat default
noteNames(0);   // ["C", "C#", "D", "D#", ...] C major prefers sharps
noteNames(5);   // ["C", "Db", "D", "Eb", ...] F major prefers flats

Wrap MiniZinc's event-based solver as a Promise. Implements the solve() call from Thesis' Algorithm.

Throw:

Test:

• solveModel
• integration: minizinc solves a trivial satisfy model and returns a solution
• solveModel returns the solution, statistics and status; logs info for non-OK status
• solveModel wraps solver errors for falsy solve and rejections with or without detail

Collects feedback form values, downloads the MIDI file, and opens a pre-filled mailto: link with the form data and composition parameters (theta) in the body.

Test:

• submitFeedback
• submitFeedback downloads MIDI, builds a mailto URL from form data and parameters and closes the dialog; falls back to '-' for missing form fields

Per-part time-grid; subdivision (tau) is the LCM of voice durations.

Test:

• timeGrid
• timeGrid derives tau as LCM of voice durations (1 for unknowns), T = iota * zeta * tau, and per-voice onset sets