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 0xd06bd46abfccd6ff3636edd46bcb833594c2db63c1871985fc3aa370a5a57803. Chain 2 (Bitcoin): anchored in block 954549 (2026-06-20T10:56:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a952b74d-6ecd-489a-8320-96808114477f.json and https://artists.proofprofile.net/proofs/artist/a952b74d-6ecd-489a-8320-96808114477f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
The History of Tango / Roberto Firpo - The Complete Collection, Volume 3 - Recordings 1937 - 1956
The History of Tango / Roberto Firpo - The Complete Collection, Volume 1 - Recordings 1937 - 1956
The History of Tango / Roberto Firpo - The Complete Collection, Volume 4 - Recordings 1936 - 1950
The History of Tango / Roberto Firpo - The Complete Collection, Volume 2 - Recordings 1937 - 1956
The History of Tango / Roberto Firpo - The Complete Collection, Volume 6 - Recordings 1937 - 1954
The History of Tango / Roberto Firpo - The Complete Collection, Volume 5 - Recordings 1937 - 1952