thumb|right|The Latsos Piano Duo in Teatro Metropolitano According to the Grove Dictionary of Music and Musicians, there are two kinds of piano duet: "[pieces of music] for two players at one instrum
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 0xe6c98b76af34396130d2fc81fd798461963d3926b8215858b328aa27410876b2. Chain 2 (Bitcoin): anchored in block 953827 (2026-06-15T19:59:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/fc6a5bf2-1a0a-4fe0-800e-6cb69ef3820a.json and https://artists.proofprofile.net/proofs/artist/fc6a5bf2-1a0a-4fe0-800e-6cb69ef3820a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).