The musical term alto, meaning "high" in Italian (from Latin: altus), historically refers to the contrapuntal part higher than the tenor and its associated vocal range. In four-part voice leading alto
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 0x8ab6a3afabb6d62a3c92dbb890e631b80068993d1f040c090129b56e38d236ba. Chain 2 (Bitcoin): anchored in block 953997 (2026-06-16T20:07:57Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/28131f2d-e88a-4a7c-b894-f66f1a9a5868.json and https://artists.proofprofile.net/proofs/artist/28131f2d-e88a-4a7c-b894-f66f1a9a5868.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).