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 0x57af0d0e7a4fc71053abf473e5930944b3e35689905722a2345629097b91a8b3. Chain 2 (Bitcoin): anchored in block 954533 (2026-06-20T08:57:02Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a3dcd2f7-aac4-484e-8515-37bcb4386cd6.json and https://artists.proofprofile.net/proofs/artist/a3dcd2f7-aac4-484e-8515-37bcb4386cd6.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
André Fleury : œuvres pour orgue & chant grégorien, Vol. 2
Boehm & Bach: Couleurs de l'orgue néo-baroque
Bach, Nibelle, Plé, Fleury, Litaize, & Kauffman: 20 Chefs-d'oeuvre pour orgue
L'Essor de l'Orgue en Europe de la Renaissance au Baroque