thumb|Edward H. Tarr in Hamburg (1996) Edward Hankins Tarr (June 15, 1936 – March 24, 2020), was an American trumpet player and musicologist. He was a pioneer in the revival of Baroque and Romantic er
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 0x002dbff6a0fc74b3619c602b3b5c150423fb6dd336b8d7c1144b8c0826c9dbfd. Chain 2 (Bitcoin): anchored in block 954032 (2026-06-17T01:59:41Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/3b7f8dd9-04c9-42af-b367-d39d010374aa.json and https://artists.proofprofile.net/proofs/artist/3b7f8dd9-04c9-42af-b367-d39d010374aa.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Haydn, Hummel & Others: Trumpet Concertos
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 0x2d4292509e9db35cff79293c224d1ab209c67e7162ebde22993b3725295ddc14. Chain 2 (Bitcoin): anchored in block 960497 (2026-08-01T02:22:04Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/HKI190121628 — a six-check JSON result.
Griselda, RV 718: Aria: Agitata da due venti
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2469e770fcaf4e6fe25f98dcda6e6d25011a3651f7f16441612dc42ed6ad599a. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USB8U1612695 — a six-check JSON result.