The Prague Chamber Choir (Pražský komorní sbor) is a Czech choir founded in Prague in 1990 by singers of the Prague Philharmonic Choir. It has performed concerts in Australia, Brazil, Israel, Japan, L
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 0x5255be81da20dbcf7071b7f5524e5a8cf4571af49c751d4092c64b39ef8e90ad. Chain 2 (Bitcoin): anchored in block 953758 (2026-06-15T07:48:25Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b349824e-a11a-4da0-a28f-e884d49f49d2.json and https://artists.proofprofile.net/proofs/artist/b349824e-a11a-4da0-a28f-e884d49f49d2.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Schubert: Mass No. 3 In B-Flat Major and Mass No. 4 In C Major