The Brazilian Guitar Quartet was formed in 1998 to interpret the repertoire for four guitars and make transcriptions of works from diverse periods and styles. The Brazilian Guitar Quartet is composed
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 0x95b4394eda30f786cc4054b363f452a0be3c7cd0e7cecc3831892f3e3ac4fddf. Chain 2 (Bitcoin): anchored in block 954569 (2026-06-20T14:36:29Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/b1f7f025-4699-4f4f-b2f3-7fbc0cb3107e.json and https://artists.proofprofile.net/proofs/artist/b1f7f025-4699-4f4f-b2f3-7fbc0cb3107e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Villa-Lobos, H.: Bachianas Brasileiras No. 1 / Guarnieri, C.: Danca Negra / Gomes, C.: Sonata in D Major
Canon and Gigue in D Major (arr. for guitar quartet): Canon in D Major (arr. for guitar quartet)
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 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. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaadbd4470ea7becd488c13a448a581d4f35587cab7e30c59a713fca92e6267a2. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USASX0860904.