Version 0.6.0 · final specification · 10 October 2026
The Virtual Acoustic Object (VAO) Standard is an open exchange and preservation standard for digital representations of musical instruments, mechanical music information carriers and other acoustic objects. A release connects descriptions, observations, recordings, images, geometry, interpretations, provenance, rights and exact file identities while retaining the established formats of those resources.
VAO 0.6.0 integrates the independently versioned MMIC 1.0.0 application profile and its VAO-owned mechanical-music vocabulary. It covers rolls, perforated and projection disks, pinned barrels, carrier collections and digital designs, with separate documentation, decoding, comparison and generation conformance. Native mechanical signals remain primary; MIDI is an optional, explicit interpretation.
Read the 0.5.0-to-0.6.0 changelog and migration contract. The GitHub release contains the immutable release files. The Zenodo version DOI identifies this edition; the concept DOI identifies the release series. Version 0.6.0 W3ID routing is pending; the release includes all normative resources and an offline dependency catalog.
| Purpose | Document |
|---|---|
| Understand the format | VAO Standard 0.6.0 |
| Implement mechanical music carriers | MMIC 1.0.0 |
| Review supported capabilities | MMIC conformance map |
| Implement selective delivery | Dynamic Delivery profile |
| Prepare repository deposits | Zenodo profile |
| Migrate a 0.5 release | 0.5-to-0.6 migration |
| Assess core conformance | Conformance specification |
| Process untrusted carriers | Security and privacy requirements |
The schema reference describes manifest fields. The profile index lists optional domain contracts. The release record documents identity and integrity.
A semantic release is one immutable manifest and its identified exact realizations. Several carriers can transport that release:
bootstrapembeds a small discovery/evidence entry point;preservation-closureembeds every realization and completes every group;custommaterializes a selected closure for a use case or byte budget.
Identified cross-carrier delivery from 0.5 remains available. A carrier-member
distribution pins the enclosing carrier, manifest, descriptor and exact member
identity. Selective materialization verifies byte size and SHA-256 before use.
mimetype first entry; stored; exact media-type bytes
vao-manifest.json canonical semantic manifest
META-INF/vao-carrier.json carrier ID, manifest pin, payload mapping
payload/... exact embedded realization bytes
The provisional media type is application/vnd.modavis.vao+zip; the extension is .vao.
Use Python 3.11 or newer and Node.js 18 or newer for the complete source gate.
python3 -m venv .venv
. .venv/bin/activate
python -m pip install --require-hashes -r requirements-lock.txt
python Tools/vao.py validate Fixtures/MMIC/1.0.0/roll/preservation-closure.vao
python Tools/vao05.py validate Fixtures/VAO05/workspaces/minimal
python Tools/check_release.pyThe installed package provides vao for version dispatch and vao06, vao05
and vao04 for their respective contracts. MMIC reports preserve separate core
and domain results, claimed conformance levels and explicit unsupported,
unmaterialized or access-unavailable states.
An explicit migration accepts a valid complete 0.5 workspace, preserves asset bytes and realization identities, and records a new manifest/release/carrier:
python Tools/migrate_vao05.py path/to/complete-0.5-workspace path/to/new-0.6-workspace \
--receipt path/to/migration-receipt.jsonMigration does not automatically promote provisional mechanical-music annotations into a validated MMIC claim. New claims must meet MMIC 1.0.0 independently.
The 0.5.0 release, its versioned schemas, specification, readers and fixtures remain unchanged. The 0.4.0 release remains available under its versioned paths. Private-draft 0.3 artifacts remain compatibility dependencies.
Conformance verifies the declared structure, semantics, provenance and exact bytes. It does not certify historical accuracy, physical playability or empirical performance. Reference execution supports declared forward/reverse linear clocks, cyclic and multi-turn helical traversal, selected fixed-tempo PPQN SMF 0/1 bindings, qualified alignment and linear-layout note generation. Segmented/repeated transport execution, uncalibrated clocks and bindings beyond that subset report unsupported.
The bundled MMIC vocabulary is VAO-owned. It is not an accepted MODAVIS Ontology Network module. The existing MODAVIS 0.1.0 binding is retained; conservative CIDOC-CRM 7.1.3 and EDM 5.2.8 mappings are informative.
Docs/ specifications, profiles and implementation guides
Schemas/ versioned core schemas and linked-data artifacts
Profiles/ MMIC schema, vocabulary, context, shapes and local catalog
Tools/ validators, writers, migration and projections
Fixtures/ conformance records and synthetic sample carriers
tests/ release, security, semantic and reproducibility tests
knowledge/ informative Open Knowledge Format companion
The responsible editor and main developer is Dominik Ukolov (ORCID). VAO was developed in the MODAVIS doctoral research project (2022–2026), supported by the German Academic Scholarship Foundation (Studienstiftung des deutschen Volkes).
See CONTRIBUTING.md, GOVERNANCE.md, CODE_OF_CONDUCT.md, SECURITY.md and SUPPORT.md. Normative resources use CC BY 4.0; software, tests and automation use Apache-2.0; new MMIC synthetic fixture data uses CC0-1.0 with explicit reference-code and dependency-lock exceptions. LICENSE and REUSE.toml define the authoritative per-file mapping.