New York Polyphony is a male classical vocal quartet based in New York City specializing in Early Music. The group's stated mission is to revive rarely heard masterpieces of antiquity. The quartet ha
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 0x02b490228a073b861d525b9babda9673f3d4dc48b7e0bdedef082eb43b0d50ab. 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/4ad407ba-a928-4505-9931-5c5f1cdc3dbc.json and https://artists.proofprofile.net/proofs/artist/4ad407ba-a928-4505-9931-5c5f1cdc3dbc.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Gregory W. Brown: Missa Charles Darwin (Commentary Edition)
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 0x5ddc0b4e259cb98bdd9c66db8ef858f0b8ee2be950eb670904503c0b43cd2c7b. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/SEAEA1907020 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x21bb8205b7283cefdb35fa464bd6cc9dfcd774448cf751bcb8d44169cdffe469. Chain 2 (Bitcoin): anchored in block 960200 (2026-07-30T02:37:10Z), 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/SEAEA1907050 — a six-check JSON result.
And the Sun Darkened: Music for Passiontide
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf574f178931e093cbfee698131ff37320967508a8a5f3e6ab3dc6451c99542cc. Chain 2 (Bitcoin): anchored in block 960468 (2026-07-31T21:25:57Z), 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/SEAEX2177010 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x014e0b19dad5e3376c468fc1ca7eb25557d93f53d0d1bfb9a9d8cf22b66f3030. Chain 2 (Bitcoin): anchored in block 960489 (2026-08-01T00:40:43Z), 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/SEAEX2177060 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa6d759a5e9760ddf6a523919729ae8a821fbdde43ad475e74de5fc4ae1d7fa17. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/SEAEX2177160 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4d3be5f34c177d777168ccdba8bbe1005c3b4a976ed303c403489a7b9fa36f35. Chain 2 (Bitcoin): anchored in block 959123 (2026-07-22T11:35:32Z), 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/SEAED2419020 — a six-check JSON result.