In music, ear training is the study and practice in which musicians learn various aural skills to detect and identify pitches, intervals, melody, chords, rhythms, solfeges, and other basic elements of
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 Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x24594b9515fdc93b389abc591ca3113a5ecbf3bec3ec6e01e8335b4eca383206. Chain 2 (Bitcoin): anchored in block 953996 (2026-06-16T20:04:35Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/30f3d637-8548-456f-b406-df9a77af55e0.json and https://artists.proofprofile.net/proofs/artist/30f3d637-8548-456f-b406-df9a77af55e0.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).