product-vamp/docs/composer/implementation_report.md

# Exact-target composer repair — release status

**Not released. Exact production reproduction of the four targets has not been achieved.** Valid derivations exist for all four complete event streams, but a target-constrained derivation is not an unrestricted production winner. The existing published assets remain intact. The previous release's report is [archived here](baseline_0e68f53.md); its tests and performance numbers do not apply to this rewrite.

Starting revision: `0e68f5364bb0196ab1b7087ecc186f5d7446c42b`. Preserved baseline: `build/solo_reference_comparison/repair/baseline/`. Its `inputs.json` records source/data/reference hashes and initial cache state. The sources remain `data/songs/all-of-me.xml` and `data/songs/autumn_leaves.xml`; no archive source has replaced either.

## Acceptance and target identity

The exact target files are `build/all-of-me-solo-1.xml`, `build/all-of-me-solo-2.xml`, `build/autumn-leaves-solo-1.xml`, and `build/autumn-leaves-solo-2.xml`. Solo 1 is acoustic; Solo 2 is electric. They are untouched. The optional adapter applies the confirmed guitar-written octave convention and merges ties while preserving repeated attacks. Autumn aligns at the first Gm7 in measure 2, including the entire preceding measure at negative chorus-relative times. All of Me aligns at measure 1.

The latest approved development scope allows target-guided general-rule work and shared-coefficient fitting, but prohibits stored tunes, per-song recipes and runtime target reads. No fitted model is promoted automatically. Optional development tools and their artifacts remain outside production imports and cache identities.

The baseline exact comparison returned failure: All of Me acoustic/electric had 0/3 exact matching attacks; Autumn acoustic/electric had 0/0. Differing onset positions were 205, 201, 211 and 178 respectively, and rests differed in all four. These are exact-event diagnostics, not musical-quality scores.

## Changes in this working tree

The hash-preselected phrase constructor and separate route solver are replaced by enumerable joint musical actions, one interpretable rational evaluator and bounded deterministic backtracking. Actions include ordinary notes/rests, complete degree routes, realized-theme returns/answers, colors, approaches, enclosures and anticipations. Pending treatments carry their actual future targets and deadlines across actions. Whole-line guitar placement follows selection; it cannot change the tune or inspect another generated part.

General expressive rules now cover delayed exact-target approaches, separated enclosures, reattacked anticipations and anticipated colors. Color octave enumeration no longer loses alternating F-sharp registers through rounding. The base scale vocabulary remains the same 21 collections; exceptions have typed, bounded contracts. Full target endings and source-derived pickup allocations are supported. Electric may overlap the returning vocal pickup as authorized; source vocal events remain unchanged.

Performance changes remove redundant parent catalog parsing, add content-addressed non-executable catalog JSON, memoize pure chord/color/spelling checks, and avoid building full rational contribution reports for thousands of rejected candidates. The lightweight ranking total and detailed evaluation are equal and tested. Existing independent process workers remain available.

The development fitter uses only shared whitelisted musical features and integer updates. An initial trial exposed two defects: unordered source-interval evidence and per-attack rewards that favored subdivisions. Ordered source relationships and duration-normalized rewards repaired them. A later trace exposed indistinguishable pending targets; their relative delay, step and hold now enter selection explicitly. Interrupted diagnostic trials are not reported as completed fitting or benchmark results.

## Evidence and limitations

The staged build completed with `--check`: six performance scores, complete solo XML, notation/TAB, playback assets, and independent accompaniment for both current sources. It is under `build/solo_reference_comparison/repair/staged`, not the published asset directory. The exact gate returned exit code 1:

| Output | Generated / target attacks | Exactly matching attacks | Differing onset positions | Exact result |
|---|---:|---:|---:|---|
| All of Me acoustic | 118 / 137 | 2 | 189 | Fail |
| All of Me electric | 128 / 141 | 0 | 232 | Fail |
| Autumn Leaves acoustic | 106 / 121 | 1 | 177 | Fail |
| Autumn Leaves electric | 143 / 115 | 5 | 195 | Fail |

Rests differ in every case. These results are not close reproduction, and attack counts are not a substitute for matching the requested music. The full comparison page is `build/solo_reference_comparison/repair/comparison/index.html`. It includes untouched references, the baseline and staged XML, complete solo-only and fixed-backing WAVs, opening excerpts, and exact note differences. Rendering used one neutral treatment and constant shared gains; no ear-based audition was performed.

The actual selected events and TAB were checked against all four reparsed exports: all agree. Thus these discrepancies arise in composition/selection, not from an exporter shifting the selected melody. Source vocal and electric head documents are unchanged from the baseline. Accompaniment documents changed with the shared difficulty configuration and the source-derived participation allocation; they are still independently generated. Source and reference SHA-256 values, and the previously published solo exports, remain unchanged. Evidence: `repair/asset-verification.json`.

The fitting trial was stopped after **40 completed passes of its configured 200-pass maximum**, without convergence. Every pass still had four incorrect rollouts; the best had only eight matching prefix attacks in total across the four cases. This is an interrupted diagnostic trial, not a completed 200-pass result and not a proof that every shared model is infeasible. Its best coefficients remain development-only under `repair/fitting`; none were copied to production data.

A further normal-production check of that best checkpoint completed All of Me acoustic: **5 matching attacks, 223 differing onset positions, and different rests**; it also failed the exact gate. The other fitted-model jobs were interrupted without completed exports. This is not a four-case fitted-model release test. Its completed XML and comparison are in `repair/fitted` and `repair/fitted-comparison`; the interruption is recorded in `repair/fitted-build-status.json`. The complete four-case results above use the unfitted production defaults.

The default selection trace explains an important failure. All of Me acoustic selected 29 arpeggio actions and six returns; electric selected 32 scalar actions, nine returns and one ordinary tone. No standalone rest won in either output. Many legal expressive candidates were proposed and rejected by score. The role's action-kind preferences overwhelm much of the vocabulary, and the local policy has no complete-phrase destination comparison. Adding legal actions has not repaired that selection limitation.

### Commands actually validated

All commands use `build/build_common/python/bin/python3 build/build_tools/python_runner.py build/build_common/modulus` as their prefix. Exact invocations are in [commands.md](commands.md).

- `-m unittest discover -s tests -p 'test_*.py'`: **446 tests passed in 348.905 seconds** (`repair/verified-tests.log`).
- `-m unittest tests.test_solo_comparison`: **9 tests passed in 0.083 seconds** after removing an invalid optional report link (`repair/comparison-tests.log`).
- `-m audition.dependency_check --output .../dependency-final`: passed all six roles, including an operational electric register change that changed that role's document and left the other roles intact.
- Full staged `-m generator ... --check --jobs 2 --composition-jobs 2 --export-solo-xml`: passed. The first attempt exposed an unfillable final quarter-beat; a tempo-gated sixteenth note/rest primitive and a regression test repaired that failure before the successful build.
- `-m audition.solo_compare ... --require-exact`: failed all four outputs, as shown above. This is the release-blocking musical result, not a passing check.
- Full-score selected-event/TAB verification and source/reference/published-baseline hash checks: passed (`repair/asset-verification.json`).

The staged asset run took **430.402 seconds** with two composition workers and warm generic catalog/non-solo caches. Tests and development fitting were running concurrently, so that time is not an isolated speed benchmark. Solo role times were 156.117, 228.292, 182.301 and 174.160 seconds in that run. No cold-generation speedup is claimed from these numbers. The full recorded stage timings and actual read traces are in `repair/build-profile.json`.

After other generation/rendering jobs stopped, `-m audition.benchmark --source data/songs/all-of-me.xml --role acoustic_solo --cache .../performance/cache --output .../performance/cold` took **134.722 seconds** for the role, plus 0.046 seconds for source analysis, with one worker and an empty concrete/catalog cache. Repeating it with `--output .../performance/warm` took **2.068 seconds** with a role-cache hit. Hardware/runtime: 12 reported CPUs, Linux 7.2.3 x86-64, repository Python environment; cProfile disabled. Cold, warm and parallel-full-build documents have the same hash `adcc372315aa10cae8a956cc5002700859c81cdcf4eeaa59b4ae6f8b41161baf`. Evidence: `repair/performance/summary.json` and the two benchmark records.

The requested cold-generation reduction is **not achieved**. Warm memoization avoids recomposition, but the wider action enumeration is still expensive. The historical baseline's different music, algorithm and benchmark conditions do not support a controlled speedup ratio. Candidate construction/evaluation remains the dominant recorded stage; no further beam expansion is justified by these results.

- [Active path, reproduced findings and search limits](active_path_audit.md)
- [Data migration and provenance](data_migration.md)
- [Authoritative evaluation and fitting contract](evaluation_contract.md)
- [Capabilities and unimplemented behavior](musical_capability_matrix.md)
- [Independent-input checks](dependency_proof.md)
- [Reproduction and exact-release commands](commands.md)

Detailed winning/runner-up contributions, selected note groups and proposal/valid/retained/selected counts are in `build/solo_reference_comparison/repair/decisions.md`. Superseded diagnostic logs are consolidated in `repair/diagnostic-history.zip`; current evidence, the baseline and targets remain intact.

The search is a local action policy, not a global complete-phrase optimizer. Dedicated suspension/blues constructors and two-sided phrase revision are not present in this replacement; validators remain. Source influence and the short realized home theme are limited models of melodic identity. A catalog containing thousands of paths does not mean all those paths currently compete as complete musical ideas. No new held-out source-standard evaluation set was added. Existing synthetic transposition/meter/harmony tests do not establish generalization to an unseen standard or subjective musical quality.

The earliest demonstrated remaining failure is selection: legal target-compatible actions lose even at the opening, and later action choices collapse toward a few favored families. The next justified investigation is whether a shared context model can distinguish those conflicting choices over complete phrases, before adding more rules, expanding the beam, or running another long fit. The finite trial here does not settle that question. There is no automatic fallback to reference notes or previous output.

Technical completion, exact target equality and listener preference are separate. No ear-based audition is claimed. The release remains blocked unless all four unrestricted exported comparisons pass; a valid or stylistically plausible mismatch is not substituted for that requirement.