John van Kesteren (4 May 1921 in The Hague – 11 July 2008 in Jupiter, Florida) was a Dutch operatic tenor.John van Kesteren (Tenor) BiographyTenor John van Kesteren (87) overleden De Pers July 13, 20
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 0x74af2129d9ff57ea4cf316cf93eb7279a99211fa17e2b2e4fec4d10c311c1971. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/755c7e0a-a700-4d2f-8286-271e0bde6265.json and https://artists.proofprofile.net/proofs/artist/755c7e0a-a700-4d2f-8286-271e0bde6265.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Herz und Mund und Tat und Leben, BWV 147: II. Recit. Gebenedeiter Mund! (Tenor)
Solistengemeinschaft Der Bachwoche Ansbach
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 0x3edd7cb9136547c62c39032b7cc653827e3fb918785a64fabe42953e5bc0f42d. 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/DEF056100173.
Herz und Mund und Tat und Leben, BWV 147: VII. Aria. Hilf, Jesu, hilf (Tenor)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbfc89a29452d32425bfe497e1c75678628649d265086c2cfb343d319745471dc. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF056100177.