The choir Mainzer Domchor is the choir at Mainz Cathedral, of boys' and men's voices. It was founded in 1866 by the then bishop of Mainz, Wilhelm Emmanuel von Ketteler. History The choir of c. 140
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 0xae6b0303e15d14e678edfa6db8ed98a527db669c5d1453ba304d8986532c1dea. Chain 2 (Bitcoin): anchored in block 953657 (2026-06-14T16:43:25Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/4b54c7d9-c909-4009-b4ec-8791808a1870.json and https://artists.proofprofile.net/proofs/artist/4b54c7d9-c909-4009-b4ec-8791808a1870.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Charles Gounod: Cäcilienmesse (Messe solennelle en l'honneur de Sainte-Cécile)
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 0x65cc860bdd2c29d525873f7147490eeb5bc91ad6933be0d6b85114b44a273644. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEN421923001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb9d97af4aa159c4d5c198e8dd154ddf95de4c25f45bda927af407e99e410513a. 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/DEN421923005.
Cäcilienmesse (Messe solennelle de Sainte Cécile) G-Dur: Kyrie
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xab8f915af18481477485b56309244a9dfa4114bf7794997291239ec172bbb67a. 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/DEN421923006.
Cäcilienmesse (Messe solennelle de Sainte Cécile) G-Dur: Gloria
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbfb90052a769fb4edba57947f4c552eb5d2b60e65d4b38b38aaf6b0871fbc379. 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/DEN421923007.
Cäcilienmesse (Messe solennelle de Sainte Cécile) G-Dur: Benedictus
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1af3f50ea4ca94b5a40afb92418afeaac5c7ae8828ac92160d68e37d396d011a. 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/DEN421923011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4fbffeb94a77068bed6262b0fd074a584f8e9a1bba2cc4b7e5922aba2eae01b1. 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/DEN421923002.
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 0xe3194e42da386f5ab9cf88569d6703a1ce99e40d2925c404950e102a751aa6b2. Chain 2 (Bitcoin): anchored in block 960494 (2026-08-01T01:44:32Z), 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/DEN421923003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa20e24d1b306280dd13b78fda110a614251edc93d18386e3637ee228972b1cae. Chain 2 (Bitcoin): anchored in block 960435 (2026-07-31T16:33:26Z), 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/DEN421923004.
Cäcilienmesse (Messe solennelle de Sainte Cécile) G-Dur: Credo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5c5ff04b0551fa37dfd0c8cf8168148c0b26063687a157a808ed8369cd22622e. 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/DEN421923008.
Cäcilienmesse (Messe solennelle de Sainte Cécile) G-Dur: Offertorium
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x72d88703ad09d163f6384bc46ecaea46588200b0a8b3c7cda2b76f70cc23cd63. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEN421923009.
Cäcilienmesse (Messe solennelle de Sainte Cécile) G-Dur: Sanctus
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5356609821385720b7497bd71bce0ac7e5ea295c6ff6bc5cfcbb74b43472e4d0. 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/DEN421923010.
Cäcilienmesse (Messe solennelle de Sainte Cécile) G-Dur: Agnus Dei
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf67dba4ec2ff1acfae7934aa7ec00bc295a44db9707254fed147ad2122d0cea5. Chain 2 (Bitcoin): anchored in block 960485 (2026-08-01T00:10:46Z), 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/DEN421923012.
Cäcilienmesse (Messe solennelle de Sainte Cécile) G-Dur: Domine salvum
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x87b90cb2ed3909a47b66fca4dd745bd94cb6e79ac22a7e8b5abbfc20b041cccb. Chain 2 (Bitcoin): anchored in block 960435 (2026-07-31T16:33:26Z), 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/DEN421923013.
Advent Music - The Musical Advent Calendar
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcb1c72e7c7fcbc8680e46d04a3be4e5823dbf9544b05c8d5b40244e6a11b7a07. Chain 2 (Bitcoin): anchored in block 960473 (2026-07-31T22:27:44Z), 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/DEA550818382.
Hans Leo Hassler: Geistliche Chormusik aus dem Hohen Dom zu Mainz (Sacred choral music from the Mainz Cathedral)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf709610c5bb2a00fd0321c01fe6e5528c616623a93ef1f0ded92e771971863e7. Chain 2 (Bitcoin): anchored in block 960117 (2026-07-29T14:28:24Z), 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/DEN421418002.