Documentation

Walk the (strata, tristrata) sequence for a StrataMode run and build a ProgressionContext with distinct triad/strata/mode layers.

The triad layer is generated by the full R→E→T pipeline: at each bar, the active context's _hcOvertones is narrowed to the current strata's 5-PC chroma (prime-notation), parseContextOnce is rerun, and stepChainBody is invoked with a pcSoftBoost multiplier computed from strata / tristrata continuity against prior bars. Graph candidates (Neo4j) and consonance-fallback candidates both flow through the usual filter → score → gamma-select pipeline, with the soft-boost applied to badness at computeFallbackScoreWithBoost (fallback) and inversely to confidence in scoreByConfidence-output (graph). Single-strata containment is guaranteed by construction: the narrowed overtone set precludes any triad whose chroma escapes s_i.

Strata and mode layer bars are representative 3-PC slices of 'strataChroma s_i' and 'modeChroma m_i' respectively, rooted on the generated triad's root so they transpose with the progression.

A starting chord drawn from inside the stratum a label resolves to under this config's tonal context.

Shared with generateBest so a K-attempt loop freezes ONE valid chord: without it the loop's frozen cue is ignored (genP draws its own) and every attempt starts somewhere different, which is exactly what freezing the cue exists to prevent.

Regenerate a contiguous range of bars within an existing strata-aware ProgressionContext. Mirrors runStrataGen but seeded from the source context's provenance instead of via initialPlacement, with a one-step lookahead on the final regenerated bar so the e → e+1 seam preserves walk-graph validity under allowedNext.

By the Phase 1 invariant, any spliced sequence whose every edge satisfies allowedNext automatically produces only ModeOk bars. Maintaining adjacency at both seams (the s-1 → s seam is automatic via seeding; the e → e+1 seam is the lookahead's job) is sufficient.

Report an invalid starting cue for genP. Prints a warning naming the cue's escape pitches alongside a grid of viable triads in the starting strata. Returns silently — the caller emits an empty ProgressionContext after this.

Produce one display line per root PC in the strata, listing every distinct-by-name triad enumerated by possibleTriads starting from that root. Uses showTriad for chord naming to match the grid footer convention. Triads are padded to a uniform column width so they align vertically across rows.

Build a synthetic starter diagnostic for a genP bar 0 (the cue). The cue isn't selected from a candidate pool, so sdSelectedFrom = "starter" signals the renderer to omit the motion/γ cells.