Product Vamp

Product Vamp is a two-device sheet-music appliance.

• Raspberry Pi Zero 2 W hosts the control Wi-Fi AP, runs the display/control service in Docker, and drives a Waveshare Zero-DISP-7A 1024x600 touch display.
• Raspberry Pi Pico 2 W runs UF2 firmware for a Waveshare 2-inch capacitive touch LCD and sends menu/page commands over the Zero-hosted AP.

Python builds the complete SQLite catalog with the score assets. The Zero opens that packaged catalog read-only through Noto, without creating a database, migrating schemas, or importing JSON at startup. Runtime navigation and rendering use Ligo for the HTTP API, Luma for touch UI rendering, and Modulus for shared build/runtime utilities.

The catalog stores shared, immutable menu metadata. Complete score bundles stay in SQLite and are loaded individually when selected; snapshots and Pico heartbeats do not copy the catalog's musical JSON.

Device controls:

On the Zero, tap menu rows and switches directly; Tempo has minus/plus buttons. The main menu offers Performance and Settings.

On the Pico (and on the Zero while viewing a score):

• Tap: next menu item or next score page.
• Double tap: previous menu item or previous score page.
• Tap and hold: select the focused item, enter/leave tempo editing, or return from a score to its part menu.

The HTTP service is device-only: Pico controls, title artwork, and health checks. There is no browser remote.

Build

Configure and build the native development target:

python3 modulus.py configure
python3 modulus.py build

Release verification:

python3 modulus.py configure --target x86_64_gcc12_release
python3 modulus.py build --target x86_64_gcc12_release

python3 modulus.py run uses package/config/vamp.development.json for a headless readiness check against native build assets. vamp_zero --once checks the packaged database and referenced page/audio assets, checks runtime writes and the server bind, then exits without opening audio or display hardware. Missing or incompatible catalogs require rebuilding or reinstalling; they are never repaired at runtime. --check-config only validates configuration; --health-check probes the running service's /api/health endpoint without modifying files.

Configure/build read public packages anonymously from the khodo Conan registry, even when the project cache contains an expired login. configure --update refreshes both the exported Modulus tooling and Conan dependencies. --no-remote uses only locally cached packages. Publishing is the only operation that needs credentials. CMake checks the required Sonus and Luma APIs during configuration and reports stale dependencies early.

ARM builds use the versioned GCC 12 cross compilers. The selected compiler executables also identify internal Conan binaries, excluding old packages built with an unversioned compiler that could resolve to GCC 13. The first corrected build rebuilds missing internal packages; third-party caches remain reusable.

modulus.py is an unchanged copy of Modulus's canonical bootstrap. The project-specific build image lives in package/Dockerfile.build; tooling.docker declares its additional inputs and permits Docker socket access only for build/package commands that assemble the Zero image.

Refresh clangd compile databases, including the Pico firmware database, with:

python3 modulus.py lsp

When running directly outside the generated Modulus Docker image, set PICO_SDK_PATH before refreshing the Pico database.

Editor settings live in modulus.json under tooling.editor. Modulus generates the ignored .clangd, .clang-format, and pyrightconfig.json files; edit the JSON settings rather than these outputs. The clangd configuration routes Zero/shared code to the native compile database and Pico code to its firmware database.

Modulus also generates .nvim.lua for Neovim 0.11+ with exrc enabled. Review and trust it when Neovim asks; it preserves the existing LSP capabilities/keybindings and runs clangd 19 in the build container for this repo. Run python3 modulus.py lsp once to prepare both databases and the shared read-only header cache. Other editors can use python3 modulus.py clangd as their language-server command. Startup never downloads or builds anything, and never falls back to host clangd.

tooling.lsp.clangd configures the server executable, arguments, trusted compiler paths, and additional header roots. Product Vamp adds the bare-metal ARM compiler and /opt/pico-sdk; standard-library and SDK definitions open from an image-keyed cache under $XDG_CACHE_HOME/modulus/clangd (default ~/.cache/modulus/clangd). Set tooling.editor.nvim.enabled to false for a hand-managed editor setup. Existing unowned .nvim.lua files are preserved.

Package

Product packaging targets Raspberry Pi OS/Debian trixie on ARM64 and optionally builds Pico firmware. Set PICO_SDK_PATH when building the firmware artifact:

PICO_SDK_PATH=/path/to/pico-sdk python3 modulus.py package --update

The package command creates:

build/packages/product_vamp_arm_64_gcc12_release.tar.gz
build/packages/product_vamp_arm_64_gcc12_release.tar.gz.sha256

The tarball contains the Zero Docker archive, Pi install scripts, generated catalog database, pages, audio, fonts, Pico title artwork, and Pico UF2 firmware. Complete score JSON is stored inside catalog.db; individual JSON files remain build intermediates and are not deployed. Builds replace the same target-specific archive without a release label. The manifest and vamp_zero --build-info identify the source commit.

Run sudo zero/install_zero.sh from an extracted bundle on the Zero. Every installation resets all Product Vamp data and settings, including the control Wi-Fi profile, to the new bundle defaults. No previous database rows or configuration are migrated. Unrelated OS data and networks are untouched. Installing through the control Wi-Fi can disconnect your session; use a local console or an independent connection.

The installer probes the incoming image before removing existing application data. A failed replacement leaves Product Vamp stopped and reports an error; rerun the installer after fixing the cause. Normal service restarts do not perform installation cleanup. No automatic backup of the previous installation is retained.

Publishing the rolling generic package requires credentials only for upload:

PACKAGE_REGISTRY_USER=<user> \
PACKAGE_REGISTRY_TOKEN=<token> \
python3 modulus.py publish

Artifacts are published to the khodo generic package registry's required latest slot. Publish the updated Modulus tooling before running Product Vamp CI so packaging and publishing agree on the stable filenames. CI checks this contract immediately after configure using a tiny fixture archive, without compiling or contacting the registry. A failure here means the exported Modulus packager needs updating; rerun the full workflow after publishing Modulus, not just the upload step.

Score Assets

Uncompressed MusicXML 3.1/4.0 scores exported from Soundslice or MuseScore live in data/. Generated score JSON is not committed.

data/songs supplies the original melody and harmony. The 21 scale patterns, 2,954 relative interval paths, meter-specific rhythm catalogs, and general rules in data/composition supply musical vocabulary. Production never reads reference solos, fitted parameters, or previous music.

Six roles generate independently: acoustic accompaniment/solo; electric accompaniment/melody/solo; vocal melody. A process pool and per-role caches support parallel and incremental builds. Canonical accompaniment repeats at corresponding source-form positions and does not react to generated solos. Original vocal and electric head content remain unchanged.

The solo composer creates complete source-related melodic phrases before selection. A realized theme develops through returns, answers, register changes, arpeggio motion and complete scale routes. Phrase destinations, rhythm, rests and holds are coordinated. Both guitars use strings 1–6 and frets 1–12 without open strings. Colors, lead-ins, anticipations and suspensions need explicit harmonic evidence. No dynamics, accents or humanization are added.

--export-solo-xml (CMake VAMP_EXPORT_SOLO_XML=ON) writes generated_assets/solo_xml/*-solo1.xml for acoustic and *-solo2.xml for electric, with actual notes and TAB. These exports do not recompose music. python -m generator.compose --song ... --role acoustic_solo --data-dir data --output ... --solo-xml ... builds one independent role.

Optional comparison lives in python -m tests.solo_compare, outside production. Supply --generated-dir, explicit --reference ROLE=PATH, --form-start ROLE=MEASURE, --reference-pitch guitar-written, and --output build/solo_comparison/review; add --assets and --baseline-dir for consistent audio comparisons. References are analysis-only. The supplied targets sound one octave below encoded pitches; All of Me aligns at measure 1 and Autumn Leaves at measure 2, preserving the lead-in. Closeness is reported using actual notes and timing; matching statistics or technical validity do not establish musical preference.

See Independent Musical Generation for the active pipeline and limitations. Keep just one compact baseline and the latest comparison under build/solo_comparison/.

To inspect generated assets without building the full package, run:

./modulus.py python -m generator --data-dir data --output-dir /tmp/product_vamp_generated --static-assets-dir package/assets --check

The --check path compares generation invariants against tests/fixtures/performance_summary.json. Modulus owns the pinned build-only dependencies in its optional assets group, selected by tooling.python.groups in modulus.json. Configure prepares build/build_common/python; ./modulus.py python and CMake use that environment and the exported Modulus modules. Builds never install Python dependencies. After dependency pins change, run configure again. C++-only libraries do not opt in, and Python is not packaged for the Pi.

CMake builds engrave with two Python workers and share a disposable page cache under build/build_common/engraving_cache. Native and ARM packaging reuse unchanged pages; CI also retains this cache between runs. Cached musical roles are reused independently; music, playback, and catalog validation still run for every generation. Set VAMP_ENGRAVING_JOBS (1-16) to adjust concurrency, or set VAMP_ENGRAVING_CACHE_DIR to an empty CMake value to disable caching. Direct generator runs can opt in with --jobs 2 --engraving-cache build/build_common/engraving_cache --progress.

Identical notation bodies share layout and body rasterization even when titles or score identities differ; each score retains its own header, pages, music, and catalog identity. A cold namespace means no cache directory exists for the current renderer fingerprint. It does not mean that every score must be rendered independently: repeated bodies can still be reused within that build, including with persistent caching disabled. Progress separates full-score hits, body hits, newly rasterized bodies, and composed pages.

The build-time pipeline is Soundslice/MuseScore -> .xml -> musical model and rhythm plans -> part generation -> JSON, engraved PNG pages, generated_tone audio, Pico title artwork, and a read-only catalog database. Sources in data/songs/ retain the seven-section performance form. Songs generate Acoustic, Electric, and Vocal parts in their authored key, without key variants or a key-selection menu. Performance measure numbers run continuously across the complete arrangement, starting at 1 in the lead-in; they do not restart with a new section or chorus. Pickups occupy the preceding measure. Standalone comparison XMLs use local measure numbers and retain the original arrangement numbers in manifest.solo.

All generated monophonic guitar material uses frets 1–12 without open strings. Accompaniment uses all legal compact positions; a chord can extend to fret 20 while retaining at least one sounding anchor at fret 12 or below and the existing three-fret span restriction. Electric source-melody harmonization retains its existing placement policy. Exact source pitches and ties are preserved; unplayable or unsupported input fails explicitly rather than being silently octave-folded.

There are no genre presets or runtime composition. The complete arranged score is played in reading order. The source-defined form and continuous whole-arrangement measure numbering remain unchanged.

All parts use two music systems per page, with a single system only when the score ends on an odd system. Lines break only between measures and share consistent staff/TAB widths. A measure that cannot fit at readable spacing fails with a diagnostic instead of being split. Tall notation is scaled uniformly to fit the two rows; guitar notation and TAB stay together and aligned. TAB displays frets and ties without duplicate rests; standard notation retains the complete rhythm. The generated .pages/*.png files are the same page images displayed by the product.

Electric melody prioritizes four-string chords, then melody on top. Every generated guitar voicing requires the root, the actual fifth, or both somewhere in the voicing, not necessarily in the bass. Defining chord tones remain mandatory. Acoustic chooses four connected string-voice journeys once across the canonical form, minimizing total fret travel across harmonic spans, then reuses them in every accompaniment iteration. Upper strings stay fixed; bass movement counts both fret distance and one step for switching between strings 5 and 6. All bass inversions are eligible. There is no acoustic register, physical-reach, or shape-effort penalty beyond its hard fret constraints. Complete triads are preferred when feasible; doubling is allowed, authored omissions are never restored, and missing optional tones break equal-movement ties. Electric chord effort balances span and distinct frets against position-center movement, without an absolute fret-height penalty. Unharmonized melody placement retains its existing register and movement costs. This is a fretboard-feasibility approximation, not a finger-assignment model. Exact melody pitches and rhythms remain unchanged.

Write all music in reading order: repeat bars, numbered endings, navigation jumps, and pass-specific ties are rejected. The seven-section performance arrangements remain fully written out. Chord labels use M, m, aug, dim, sus, and mM7, including explicit major triads such as CM. Recognized Soundslice text-only harmonies are normalized into structured chords; parenthesized chords mark optional turnarounds omitted from the final arrangement ending.

The Settings menu's Playback toggle plays the selected part once at the menu BPM, suppresses the metronome, and returns to the part menu after natural completion. Manual page turns do not seek or restart audio. Playback is off by default. Python generates shared PCM tones and exact beat timelines; C++/Sonus only loads, schedules, and mixes them. Audio sample sustain loops hold individual notes for their written duration; they never repeat musical passages. No SoundFonts or runtime synthesizer are required. The main menu contains Performance and Settings. Settings holds Playback, Metronome, and Tempo; its values apply for the current session. Navigation is Song -> Part -> Score.

Code style is managed by Modulus, using compact two-space formatting. Python imports modules by their full names and qualifies imported symbols; only from __future__ import annotations is exempt, and imports have no aliases. Run ./modulus.py format to format C++ and Python, or ./modulus.py format --check to check formatting and prohibited aliases. The project-local Neovim integration routes Conform formatting through the same container tools, including format on save and existing LazyVim toggles. Run configure first when the image or exported tooling needs updating. Use tooling.editor.clang_format for C++ overrides and tooling.format.exclude for project-relative exclusion globs; do not edit generated .clang-format files.

Use American English in project-owned identifiers, filenames, messages, and documentation, such as catalog, color, and canceled. Preserve authored music and external API names.

See Score Generation for supported MusicXML notation, Vamp properties, schema details, and diagnostics. There is no compact-JSON source format or legacy runtime adapter. Unsupported notation fails generation before existing assets are replaced.

Build-time engraving is implemented in Python in generator/engraving, using the bundled Petaluma OTF fonts and SMuFL metadata. MuseScore is an optional authoring tool, not a build dependency or rendering backend. Configure installs the optional Modulus asset dependencies. Exact musical timing is retained through layout, with line breaks between complete measures. Missing glyphs, unrepresentable page geometry, and failed notation audits stop generation before replacing existing assets.

generator/palette.json supplies the dark gig theme for Zero, Pico, score pages, and previews. CMake generates the shared C++ colors from the same palette used by Python. Palette changes invalidate the engraving cache without changing music, spacing, or pagination.

Petaluma is from Steinberg under the SIL Open Font License. Petaluma supplies music glyphs, and Petaluma Script supplies all visible text on score pages and both device interfaces. The Zero uses packaged PetalumaScript.otf for dynamic UI text; the Pico displays prerendered Petaluma Script artwork. Runtime packages retain OFL.txt; the music font and engraver stay build-only.

Pico artwork generation requires Pillow's Raqm layout support to preserve kerning. On Debian/Ubuntu, install libfribidi0 alongside the pinned Python requirements. The build image and CI install both. See Pillow's installation requirements.

Pico firmware embeds a small set of fixed labels, part names, digits, and the page separator, generated as four-bit coverage sprites under generated/pico/static.p4. Score generation prerenders titles into content-addressed pico/titles/*.mask assets referenced by the catalog and served by the Zero when the selection changes. Pico blends those pixels and composes page counts from digit sprites; it does not load fonts, shape text, or rasterize glyphs. All Pico text shaping and artwork generation run on the build host. The build image and CI install the pinned dependencies automatically. For a direct build, first run:

./modulus.py configure

To inspect the fixed artwork independently, run ./modulus.py python -m generator.pico_artwork --static-output /tmp/product_vamp_pico/static.p4. Changing the source OTF or artwork generator rebuilds the firmware sprites and generated title assets. These generated files are not authored music and are not checked in.

License

Product Vamp is released under the MIT License. Bundled third-party fonts keep their own licenses next to the font files.