Concerto Amsterdam was a classical chamber ensemble based in the Netherlands and active during the 1960s and 1970s in both live performance and the recording studio. It was founded in 1960 by the Dutc
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 0xa0fcf23daa88ad04f1d49457e3e53cd05c63f017ae3a1dc801141b2ff65c5559. Chain 2 (Bitcoin): anchored in block 953620 (2026-06-14T09:36:10Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/1e26086d-8589-4ef4-b913-868252b8b5c9.json and https://artists.proofprofile.net/proofs/artist/1e26086d-8589-4ef4-b913-868252b8b5c9.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).