Jay Leonhart (born December 6, 1940) is an American double bassist, singer, and songwriter who has worked in jazz and popular music. He has performed with Judy Garland, Bucky Pizzarelli, Carly Simon,
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 0x9c4bdf1a6a2bace2bdbc8f74e04119f564cc18f70a2e1ff1dcc97b426ffb543d. Chain 2 (Bitcoin): anchored in block 953687 (2026-06-14T20:19:15Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/6a26ff14-6f0e-4326-bacd-6f709bb3be7e.json and https://artists.proofprofile.net/proofs/artist/6a26ff14-6f0e-4326-bacd-6f709bb3be7e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Best of the Essential Years: Jay Leonhart