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 0xf165a8a933031dfe4146ef9a7cf0b5d85d846c47fcf7d4fcc03343aa7171ed76. Chain 2 (Bitcoin): anchored in block 954693 (2026-06-21T11:50:32Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/e72c00cd-5f70-455b-8c03-82a5f03cc98f.json and https://artists.proofprofile.net/proofs/artist/e72c00cd-5f70-455b-8c03-82a5f03cc98f.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Lutoslawski: Dance Preludes / Faith: Sea Pieces / Genzmer: Sonatine / Alwyn: Clarinet Sonata
Indy: Clarinet Trio in B-Flat Major / Muczynski: Fantasy Trio / Brahms: Clarinet Trio in A Minor
Poulenc / Dunhill / Bax / Bernstein / Schumann: Sonatas for Clarinet and Piano