The Maulbronn Chamber Choir (German: "Maulbronner Kammerchor") was founded in 1983 and is directed by Jürgen Budday. It took first place at the Baden-Württemberg Choir Competition in 1989 and 1997, s
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 0xb4c46ab1bfafdd53eee60e52b4be2f59dd00dc257db43f63b03953d52f96a59b. 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/4f8c3b9e-2af8-4a48-a858-feed4ae302dc.json and https://artists.proofprofile.net/proofs/artist/4f8c3b9e-2af8-4a48-a858-feed4ae302dc.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Handel: Samson (English Oratorio HWV 57, performed according to the traditions of the time)
Solomon, HWV 67: Part III: Sinfonia, "Arrival of the Queen of Sheba"
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 0xaa3dd91463f4b8a9b4f21513d8e8e5a0f40e68c25fa2b4b5facac7b25354d432. 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/USB8U1020587.
Solomon, HWV 67: Part I: Your harps and cymbals sound
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0d7ce863a190bdd4d6943a3b113238880e9b3e9f3f145dd681c54f30b7c9d6b7. Chain 2 (Bitcoin): anchored in block 960298 (2026-07-30T19:26:00Z), 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/USB8U1020586.
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