thumb|upright=1.2|Machaut (right) receiving Nature and three of her children. From an illuminated Parisian manuscript of the 1350s Guillaume de Machaut (, ; also Machau and Machault; – April 1377) w
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf6ef3bb2cf4f25d6f38c3f216978f9e7405255e9ab1540937e37073f57fe8147. Chain 2 (Bitcoin): anchored in block 953423 (2026-06-12T21:20:00Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2956b6c4-de7e-4984-a51b-c326c944ad71.json and https://artists.proofprofile.net/proofs/artist/2956b6c4-de7e-4984-a51b-c326c944ad71.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3d8cd37e2ef27feb387d276b3ff69b6bea2e6b5830d7cb7d5571ef9a34507b79. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300370.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x141b3633cf87a54310b32bab0cbf03ad787f7af9d3f129778bc6ad5a5dc243a4. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300380.
Dix et sept, cinq, trese, quatorse et quinse
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbd6ab23d5c2eb7ba21880ed0694f6607f7603f898d0d151fe5cd87ba04541685. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300430.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x59c2a34b4dd546a5f2037699391728b09bc80ba7b5b173c1773e796d0b3019ea. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300450.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc4510f1c899c6d250cd2de1cd851fbec254d8f7b9b6c96ce51a7964865f1869f. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300390.
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 0x639789f6061cc139a22bfdbc093a54ad8ca26a12ae31c642cb8d15a7fb5a9ca6. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300400.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd63255364806756a5b05ac0df93ec43757186be7e92730fc401845c683e48e3e. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300410.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb0bb77f153bc598c11860e42c6cea8760dff796a22110f6e469ae4002eb04322. Chain 2 (Bitcoin): anchored in block 960317 (2026-07-30T21:35:24Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300420.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf38de017b357c6732ae1648457e5674288b565d8c851af0445963d5eb9700b29. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300440.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa003d1081d7b3e27fe42b738f3cb8ea3577c4fc4c1761dc0f119a2453f62f80a. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300510.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x00d681f44ea722ae47e458cff0025ecc80885fb3e572d21e524f3f22ed9d02b8. Chain 2 (Bitcoin): anchored in block 960095 (2026-07-29T11:07:37Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR6V51300520.
Guillaume de Machaut: Remede de Fortune (Live)
Quant en moy - Amour et biauté - Amara valde (Motet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xff90b8ec63cfe149eec172175ef7d766001e8349d0f0e478f835fb79aa091c6e. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRW189800042.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8fa2216a11b2db6e7e74f2ac3018803d5d9b271a08d6a1d39723a1cfbf97ad6c. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRW189800043.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x423534c16b240482e8488edac7063b180f98a240d47cbc8d3456aef9d85bbade. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRW189800046.
S'Amours ne fait par sa grace adoucir (Ballade)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xebdf98dc9718a11f64a506bfd04a3998d0bd2e4b1a6e4e8b915d17093c5badaa. Chain 2 (Bitcoin): anchored in block 960455 (2026-07-31T19:53:13Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRW189800044.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7261f0899a3b0caf629a3b1c17cbba59af2cb29fdbb4fc3283ec37652884ff43. Chain 2 (Bitcoin): anchored in block 960170 (2026-07-29T23:52:38Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRW189800054.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x089c24bc2f132e3ed7ff41dd502bedc6c48463362acb791b531ea481de7a2533. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ177300120.
Dame, ne regardes pas (Medieval Fiddles)
Dictionary of Medieval & Renaissance Instruments
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9941a5cffd48401a03a5183902f825c35f8e74edd34887d3a1f250993dbeba41. Chain 2 (Bitcoin): anchored in block 956351 (2026-07-02T11:38:34Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/MX2831000690.
Brian Gulland/David White/Peter Lockett/Theodossii Spassov/Hughes de Courson
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x824af0c2cfac0a9bdf86b5c7803e9a4008cd054fd4a2380ecf522cdbc5307d01. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR34F0300130.
Joie, plaisance (Medieval Fiddle & Ensemble)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9935f03df92f2f0b9db1c81aa9f639bd69c924befbf88d69344229dcbe02e5bf. Chain 2 (Bitcoin): anchored in block 960294 (2026-07-30T18:46:00Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/MX2831000692.
Meditation Music: Meditative Music Across Ten Centuries
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2dee25d60c478fd22555eaaac2ff9bae7570e775b3c158319eeabbf2db36c463. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/ES7141500237.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6491a1a672daf237e5fa0969a16c2134c9870fd5dbe3323596966c506aa5d1a2. Chain 2 (Bitcoin): anchored in block 960163 (2026-07-29T23:20:38Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF057502680.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe6c6f78d45dfce200208d1223e761f8638994e968de2704a3315e22b90683e0b. Chain 2 (Bitcoin): anchored in block 960236 (2026-07-30T09:37:10Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/MX2831000716.
Honte, paour, doubtance (Pair of Medieval Recorders)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf693ce83141d0bf248aad50d1ad48ee66dafab73861a0b53ba545830a7aec008. Chain 2 (Bitcoin): anchored in block 960294 (2026-07-30T18:46:00Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/MX2831000718.
Dame, vostre doulz viaire (Arr. for psaltery by Anna-Liisa Eller)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6a41c95dd865cee65d41c73a4dc6b4435c0987114135c3743544fe811a77117d. Chain 2 (Bitcoin): anchored in block 960321 (2026-07-30T22:27:30Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR7JM1906060.
Brian Gulland/David White/Gilles Chabenat/Hughes de Courson
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x19f77cf7f2c582b8c7fdc14827671732131edce306f0c2781193c0945bb1f9f3. Chain 2 (Bitcoin): anchored in block 960340 (2026-07-31T03:15:04Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR34F0300060.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x536155f077910d20450e8437d1d5950606fa93096ca8aaa395a2a4745a57efdf. Chain 2 (Bitcoin): anchored in block 960344 (2026-07-31T04:14:58Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF057502690.