Marcel Pérès (born 15 July 1956, Oran, Algeria) is a French musicologist, composer, choral director and singer, and the founder of the early music group Ensemble Organum. He is an authority on Gregori
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 0xb28553498ebdd6fdfa58ce274543f1848f7b3b0cf06e1d08056f07d7a987b165. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a39b5ea4-2099-4cdd-bd74-0a77708284a6.json and https://artists.proofprofile.net/proofs/artist/a39b5ea4-2099-4cdd-bd74-0a77708284a6.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Chant de l'Eglise de Rome (VIe - XIIIe siècles)
Gradual of Eleanor of Brittany: Kyrie: Orbis factor
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 0xa27a0a34386b8a2d969947f17599acc53d66dbfee03d0282f6711ada877da0e4. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/FRZ149136020 — a six-check JSON result.
Répons de Matines pour la Fête de Saint Bernard: "In Timore Dei"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x726dce740e6e4f1d4c851f60ceedd9d8fda3fa77f3a2fe2d697b7a56de760c42. 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/FRZ149107080 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0a295d9e2b377367e1071ec5c345591fd167742877299edf8a1140eec7c3ea3c. 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/FRZ148417020 — a six-check JSON result.
Chant of the Church of Milan: Lucernarium, Paravi lucernam Christo meo
Voices from Ancient Abbeys: Plainchant & Polyphony
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd3fac0cfd9997f5ddee1c4ba9ab6305d89b642e858e389c5e2f94375c27757a0. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FRZ148910010 — a six-check JSON result.
Chant of the Church of Milan: Alleluia - Versus "Hodie in Bethlehem puer natus est"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0efe91670c404b568df918f40bd2864080f831f41b865e413ef82df630001849. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/FRZ148910060 — a six-check JSON result.
Chant from Benevento Cathedral "The Adoration of the Cross": Antienne "Otin to stauron" - "O quando in cruce"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa0524b733d4c758acd66ad4db6c53934b7744e8730792699bf32972509149733. Chain 2 (Bitcoin): anchored in block 959128 (2026-07-22T12:33:25Z), 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/FRZ149321010 — a six-check JSON result.
Chant from Benevento Cathedral "The Adoration of the Cross": Répons "Amicus meus osculi me tradit" - Verset "Retulit triginta argenteis"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x08653f1a8fbeaa885ded3e7a811ef6eec7ef0aefae62e9e1a2582fd834f5a8d2. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FRZ149321060 — a six-check JSON result.
Chant of the Church of Rome Byzantine Influences: Offertorium, Terra tremuit V. Notus in Iudea - V. Et factus est in pace - V. Ibi confregit
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x65d53ec591cc777e918d7e6b2a34f0ac54d9c83f475bec38783c08407fa13d22. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ148513050 — a six-check JSON result.
Old Roman Chant, Vespers of Easter Day: Antiphona Alleluia. Psalmus 110 Confitebor. Antiphona Alleluia
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x636d8d64f8b827d4f07d8f101dbe1bbe46873eeb4b4d7918655741cff3d316c5. Chain 2 (Bitcoin): anchored in block 959118 (2026-07-22T10:01:58Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ149752030 — a six-check JSON result.
Old Roman Chant, Vespers of Easter Day: Oratio Concede questimus
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb0c58ae12e1b1c3683b3549284ec2b56604967b5bf7b6ab45e7cb8b493f8386e. Chain 2 (Bitcoin): anchored in block 959128 (2026-07-22T12:33:25Z), 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/FRZ149752080 — a six-check JSON result.
Old Roman Chant, Vespers of Easter Day: R. In die resurrectionis. V. Congregabo gentes
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfab86ddeab29d5091f0135b0273e9039bbba1dc817e9c9d032994fa3ff355630. Chain 2 (Bitcoin): anchored in block 959103 (2026-07-22T05:56:21Z), 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/FRZ149752090 — a six-check JSON result.
Cistercian Chant Responsories of Matins for the Feast of St Bernard: Prima virtus viri sancti
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x27c1311541df37b528bd9ab51aff95c575d6a704985c54d43b7531a7fb1adacb. Chain 2 (Bitcoin): anchored in block 956894 (2026-07-06T07:53:57Z), 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/FRZ149107060 — a six-check JSON result.
Cistercian Chant Responsories of Matins for the Feast of St Bernard: Testamentum eternum
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xabb5f0cf0e581827bdb336a73f7690523ec5a3d1646428712225c5ee82e8e480. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ149107110 — a six-check JSON result.
Cistercian Chant Responsories of Matins for the Feast of St Bernard: Oliva fructifera
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x39e450754000c093fc5d16f7d43b4e1bea209c972f4c7920804796634c30a4ba. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FRZ149107120 — a six-check JSON result.
Cistercian Chant Responsories of Matins for the Feast of St Bernard: Dedit Dominus confessionem sancto suo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x48a9d73b178d194148dc033a69df139a707f4ad145318d42d08e8c7f3c5b4ee8. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FRZ149107130 — a six-check JSON result.
Mass for the Nativity of the Virgin: I. Conduit monodique "Beata viscera Marie Virginis"
École de Notre-Dame de Paris : Mass for the Nativity of the Virgin
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x02b185556a5577698722d578a7d54d134366292656927b0f459763a25818d660. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FRZ149434010 — a six-check JSON result.
Mass for the Nativity of the Virgin: II. Conduit à quatre voix : Deus misertus hominis
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x81d71db4dc4c5750e928ba2d92d090947ee04eaab5d9fb613ca18abc646e13f7. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/FRZ149434020 — a six-check JSON result.