Marcus Batista Belgrave (June 12, 1936 – May 23, 2015) was an American jazz trumpet player from Detroit, born in Chester, Pennsylvania. He recorded with numerous musicians from the 1950s onwards. Belg
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 0x8e78edb2113205c2a84c05489c2d5d30cf7a60b80b6724289ed73873be0b121e. Chain 2 (Bitcoin): anchored in block 953633 (2026-06-14T12:47:11Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/33de7e9b-e72c-4183-aa88-92028697a821.json and https://artists.proofprofile.net/proofs/artist/33de7e9b-e72c-4183-aa88-92028697a821.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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 0x7459dc7db37499f503e70f537fd10bbad3eedc6e99e620808057cc4f0e1fccc3. Chain 2 (Bitcoin): anchored in block 958891 (2026-07-20T16:03:11Z), 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/USL4Q0809623.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x000c202b0dc7a6ba6dd1e71d768620a121f21a6f094ed7d4deed14cbecf7f32f. Chain 2 (Bitcoin): anchored in block 958303 (2026-07-16T16:39:24Z), 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/USL4Q0809626.