Walter Levin (December 6, 1924 – August 4, 2017) was the founder, first violinist, and guiding spirit of the LaSalle Quartet (active 1947–1987), which was known for its championing of contemporary com
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 0xf9233778cf9904f05a69c459fb5c8052928343ae9601a734b086f0d43fa14956. Chain 2 (Bitcoin): anchored in block 954055 (2026-06-17T05:51:24Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/44579858-aca0-4a24-b166-438878a37131.json and https://artists.proofprofile.net/proofs/artist/44579858-aca0-4a24-b166-438878a37131.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Debussy: String Quartet In G Minor, Op. 10 / Ravel: String Quartet In F Major
Brahms: String Quartets Op. 51 Nos. 1&2; String Quartet No. 3, Op. 67 / Wolf: String Quartet In D Minor "Entbehren Sollst Du, Entbehren"