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 0xa8d1a3c7e9876db8879783c31974a5bd81c5ac3b1132570674ceaab94041f4ed. 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/f34425af-a933-4ab1-bd40-c3108999c006.json and https://artists.proofprofile.net/proofs/artist/f34425af-a933-4ab1-bd40-c3108999c006.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Vaccai: Practical Vocal Method (Accompaniments for Medium Voice)
Vaccai Practical Vocal Method Accompaniments for Bass and Contralto with transpositions