Public-Domain Verification Process

1. Policy: United States public domain only

Attacca ingests, stores, and serves only musical scores verified to be in the public domain in the United States. A file that may be public domain in another jurisdiction but not the United States is excluded from the catalog entirely. This is deliberate conservatism. Attacca operates from the United States, and a single strict standard is simpler to verify, to audit, and to defend than a per-jurisdiction model.

2. Verification pipeline

Files are checked at every stage from ingestion to delivery. Source review supplies the initial copyright data; three independent gates then exclude any file that is not United States public domain, at ingestion, at download, and at catalog inclusion, so a file that fails any one of them never reaches a user. A fourth gate governs serving, delivering only the already-cleared catalog through authenticated, metered access.

• Source review. Each file in the source archive carries a copyright-review tag covering the United States, the European Union, and Canada separately. That tag is the starting datum, not the final word.
• Gate 1, ingestion scope. Our extraction step reads the per-file tag and places a file on the download list only if it is marked public domain in the United States. Files that are not US public domain are never downloaded.
• Gate 2, downloader. The crawler enforces the same check independently and refuses to store any file absent from the verified list. The check is enforced in code and cannot be bypassed silently.
• Gate 3, catalog build. A file enters the catalog only if its individual US-public-domain verdict holds. The verdict is per file, not per work (see Section 4).
• Gate 4, serving. Only files that passed Gate 3 enter the catalog, so every score available to download is public domain in the United States. Files are served solely through authenticated, metered download grants, never directly, and each retains its per-file audit record. Editions admitted under the urtext analysis (Section 5), and only those, present an explicit acknowledgment at the point of download. Attacca applies one United States public-domain standard uniformly and does not detect or filter by a visitor's location. Public-domain status can differ outside the United States, and users there are responsible for compliance with their local copyright law, as set out in our Terms.

3. Audit log

Attacca maintains a durable, per-file audit record.

For each file examined, the record captures:

• the source URL;
• the date the file was examined;
• the raw upstream copyright tag;
• the resulting per-jurisdiction public-domain verdict;
• the ingestion decision, admitted or excluded, and on what basis.

The log accumulates over time and is not overwritten. For any file in the catalog, Attacca can therefore state on what basis, and on what date, it was judged to be in the public domain. This is what makes the process auditable rather than merely asserted.

4. Edition-level copyright

Public-domain status is judged at the level of the individual digitized file, never the composer or the composition alone. The most common error in score reuse is to treat a public-domain work as though every edition of it were equally free. A modern critical or engraved edition of a public-domain composition carries its own copyright. Attacca's per-file gate is built specifically to exclude such editions, even when the underlying work is unambiguously in the public domain. Section 5 below addresses the narrow class of older urtext and re-engraving editions where the legal analysis differs.

5. Urtext and re-engraving editions

A narrow class of files in the catalog comes from urtext or scientific editions of public-domain compositions. The legal analysis for these files differs from the general edition rule in Section 4 and warrants direct disclosure.

Such editions are in the public domain in the European Union where the scientific edition right has expired, and in Canada, which does not extend copyright to re-engravings of public-domain works that fail to meet the threshold of originality. The United States position is that copyright applies only to original creative work; the re-engraving of a public-domain composition, without the addition of substantial new creative material, does not qualify for new copyright protection.

Attacca admits files in this class only when the upstream source both identifies the file as an urtext or re-engraved edition of a public-domain work and bears no explicit notice that the edition itself remains under copyright in the United States or European Union. Two different signals must not be conflated. The structured per-jurisdiction copyright tag (see Section 2) applies the general edition rule mechanically, and for a faithful re-engraving that adds no new original authorship it may read as copyrighted in the United States; consistent with Section 2, that tag is a starting datum and does not, on its own, exclude a file. An explicit copyright notice is different: any file whose source materials affirmatively assert that the edition itself is separately copyrighted in the United States or European Union (as distinct from the mechanical jurisdictional tag) is excluded categorically, regardless of any other consideration. A file not affirmatively identified as an urtext or re-engraved edition is likewise excluded.

Each file admitted under this section is presented to the user with an explicit notice at the point of download, identifying it as an urtext edition admitted under this analysis, so the user can make an informed decision before downloading.

Files admitted under this analysis are marked in the audit log with a distinguishing provenance flag. The entire class can be identified and retracted in a single operation if a publisher dispute or further legal review ever requires it. If you believe any specific edition has been incorrectly classified, please contact us through the DMCA process.

6. Foreign works and URAA restorations

Foreign works first published between 1923 and 1977 receive elevated scrutiny. The Uruguay Round Agreements Act of 1994 (URAA) restored United States copyright on foreign works that remained under copyright in their source country on January 1, 1996. A work that appears to be US public domain by publication date alone may in fact be subject to URAA restoration, with US copyright extending until 95 years after first publication.

Our source review accounts for URAA at the file level. The per-file copyright tag we ingest reflects a review of both the US publication-date analysis and the source-country copyright term as of the URAA restoration date. Files implicating URAA are admitted only where the source determination is unambiguous; uncertain or recently restored works are excluded. This is the area of US public-domain analysis that most often produces close calls, and our default is conservative exclusion.

7. Content sourced through institutional partnership

For scores obtained through a partnership, the partner institution's own public-domain determination is the primary basis for inclusion. A library that digitizes only works it has itself determined to be in the public domain, under a documented and conservative standard, arrives pre-vetted. Attacca's gates and audit log then serve as a documented confirming check rather than an independent re-adjudication, and every item permanently retains its source identifier as a provenance link back to the originating institution.

8. Legal posture

For the catalog, Attacca's position rests on substance rather than procedure: the content is genuinely in the public domain, so there is no copyright to infringe. The verification pipeline and the audit log exist to make that claim demonstrable, file by file. Should a mislabeled file ever be identified, Attacca can remove it from the catalog promptly, and will do so on any credible report, with the audit log preserving the basis of the original decision for review. Conservatism in what is admitted, documentation of every decision, and prompt correction are treated as the core of responsible operation.