Leonel Power (also spelled Lionel, Lyonel, Leonellus, Leonelle; Polbero), c. 1380–1445, was an English composer of the early Renaissance. Along with John Dunstaple he was a dominant figure of 15th-ce
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 0x99a339cba64a95c3b9a6f1964ebd7ca5d01be91ef6c512622ad59a4d2e141763. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/8ec7e1f6-69f3-4b88-8c4e-018301dd9629.json and https://artists.proofprofile.net/proofs/artist/8ec7e1f6-69f3-4b88-8c4e-018301dd9629.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Ars britannica. Old Hall Manuscript, Madrigals & Lute Songs
Wilbye: The Second Set of Madrigals: No. 15, As Matchless Beauty
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 0x77979139d0b4f09ac3987a164b54be2776ad2d1a6d22355054dc0f1a261d2051. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/DEA808000022.