François d'Agincourt (also d'Agincour, Dagincourt, Dagincour) (1684 – 30 April 1758) was a French harpsichordist, organist, and composer. He spent most of his life in Rouen, his native city, where he
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 0x8e937552591446231f006bfea673d2a9a413aa8108fb0de2038f380d764c8587. Chain 2 (Bitcoin): anchored in block 954346 (2026-06-19T03:51:26Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/933e4261-1ee0-4539-ae27-97ac31ec0298.json and https://artists.proofprofile.net/proofs/artist/933e4261-1ee0-4539-ae27-97ac31ec0298.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
François d'Agincour: Complete Works for Harpsichord, Volume 1
François d'Agincour: Complete Works for Harpsichord, Volume 2
D'Agincourt : Missa in assumptione beata Mariae virginis
Pièces de clavecin, Second Ordre en fa majeur: II. Le Colin-Maillard, rondeau
D'Agincour: Pièces de clavecin, 1733 - Vol. 1