1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x163d310ba928bba7d042864cf38a3a0460341343d46b3303e947959759fcd384. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/88c88dfd-fbd8-4a43-a7a4-2c57e0fcc7b3.json and https://artists.proofprofile.net/proofs/artist/88c88dfd-fbd8-4a43-a7a4-2c57e0fcc7b3.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7fb0440c618d4db93e4831ae5b5b6883830ec48e382acd7c12154f0706181ad5. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12220001 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb47439d3a472c1c3b0232df55d06d1b251877cace3d3cf4edd6dfa09748131be. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12220009 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb5127b4ab6ce9c407d3bceb120704c85e34cd113440fee111d2193c1358950f0. Chain 2 (Bitcoin): anchored in block 960497 (2026-08-01T02:22:04Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12220016 — a six-check JSON result.
Mozart: Twelve Duets For Two Horns K487 (K496A)
12 Duets For Two Horns, K. 487: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5e8aa6cc97d4a1b34ed2fb07cde2a15ddd3b422cf611b0c0e96564b7854ac5fa. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210001 — a six-check JSON result.
12 Duets For Two Horns, K. 487: II. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x25ed1429b96bdf5ed9c1ca5f0d640625bb76f60d033f7522d5c2476aa9f2241f. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210002 — a six-check JSON result.
12 Duets For Two Horns, K. 487: III. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x93657e5d22f83e46895bc3809a344d519c828f451c8c8c519c955414e0338ac4. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210003 — a six-check JSON result.
12 Duets For Two Horns, K. 487: IV. Polonaise
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x412e437ea3d83470b17ca61c760fde2c7000bcf5c12ca248c6b4243751c16026. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210004 — a six-check JSON result.
12 Duets For Two Horns, K. 487: V. Larghetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5e2ddd06d261a93549f0803529a4bd185d0008683d01360f7a69a1ae57753cd5. Chain 2 (Bitcoin): anchored in block 960334 (2026-07-31T02:19:15Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210005 — a six-check JSON result.
12 Duets For Two Horns, K. 487: VI. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xffc696755337927cecce3a9de8ad351963f863838437135a6916b522130b1dd8. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210006 — a six-check JSON result.
12 Duets For Two Horns, K. 487: VII. Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x08166cf72f4a3cafb6d6ea29242562e8cae89dc235aa47a2204ab74d2063d590. Chain 2 (Bitcoin): anchored in block 960404 (2026-07-31T13:06:57Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210007 — a six-check JSON result.
12 Duets For Two Horns, K. 487: VIII. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x31ceb5c8e1ccf5ae34d3258a49d2ce3fb265a8e6b1fe41c4cc1826946836ad95. Chain 2 (Bitcoin): anchored in block 960463 (2026-07-31T20:42:35Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210008 — a six-check JSON result.
12 Duets For Two Horns, K. 487: IX. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x61a35c535596b7c97a0f0590f09e44f34d133d08060c18fc4b0ae393a12a910f. Chain 2 (Bitcoin): anchored in block 960448 (2026-07-31T18:48:12Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210009 — a six-check JSON result.
12 Duets For Two Horns, K. 487: X. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe40eecbc53b11ff3baa0c918e0c028735212cecb43ce1d93f83e37b7d018a34b. Chain 2 (Bitcoin): anchored in block 960500 (2026-08-01T03:13:03Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210010 — a six-check JSON result.
12 Duets For Two Horns, K. 487: XI. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe792b9c40ee1c90123de4fa76685de230072b10a9913bd009b284c0f7c1b15ad. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210011 — a six-check JSON result.
12 Duets For Two Horns, K. 487: XII. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5fef2bce7d2f5064daea766c76b9a45f515781e928704ff283c1e9c8dfc0405a. Chain 2 (Bitcoin): anchored in block 960468 (2026-07-31T21:25:57Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DE1E12210012 — a six-check JSON result.
Siegfried und Violetta oder List, Last, Lust und Lunge
Beethoven's World - Beethoven, Wranitzky, Reicha, Vorisek: Concertos
Concerto for Two Violas and Orchestra in C Major: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf1f1548195f032894cf0221121676f375c0c34bf835421cc96ab39359bf6442c. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEE862002759 — a six-check JSON result.
Concerto for Two Violas and Orchestra in C Major: II. Romance
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd058f8c66f27c2124d33cb8c14e1930574d62522d0c92f954c9b5e9b8bf92ee6. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEE862002760 — a six-check JSON result.
Concerto for Two Violas and Orchestra in C Major: III. Rondo. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbbdfa83818269de40323f660813935bae856abd613504b01a4ca739a1a16c77e. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEE862002761 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x29d67913ccef15cf183d26bae902cda31bee4449e278370f8c6d49ab967808a2. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DET901225201 — a six-check JSON result.
Horn Sonata, Op. 24: III. Moderato, e poco rubato
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb4ff652652353aab23c2e1c4f9d7447eb3ce193222f735a565fb74a42e2a1ce8. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DET901225203 — a six-check JSON result.