thumb|Ernesto Halffter Ernesto Halffter Escriche (16 January 19055 July 1989) was a Spanish composer and conductor. He was the brother of Rodolfo Halffter and part of the Grupo de los Ocho (), which
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 0x291f75c4111f9a6a59b51faaf6b231fd4bac137c92fb54188b3757e686b3816b. Chain 2 (Bitcoin): anchored in block 954588 (2026-06-20T19:15:05Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/bc304b97-9b1b-4f1b-a9bf-da5ffe002682.json and https://artists.proofprofile.net/proofs/artist/bc304b97-9b1b-4f1b-a9bf-da5ffe002682.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Smörgasbord: Encores and Short Pieces for Cello and Piano