Leon Fleisher (July 23, 1928 – August 2, 2020) was an American classical pianist, conductor and pedagogue. He was one of the most renowned pianists and pedagogues in the world. Music correspondent Eli
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 0xef39da419461686b72bdbd37feac3d9eed1152fc5062277fe0d8682eb005f3c9. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/03dfa75f-8c7c-4f70-ba2d-d8398704cf0e.json and https://artists.proofprofile.net/proofs/artist/03dfa75f-8c7c-4f70-ba2d-d8398704cf0e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
String Quartet No. 3 in B-Flat Major, Op. 67: I. Vivace
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 0x6b51751d745c536164f815ceedb6cb8995d9461647f653f97b4d1e48370e021a. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/DEN960500801.
String Quartet No. 3 in B-Flat Major, Op. 67: II. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcd67f34455efbd243a7e7c10ee7996d248f9df214820c17b66a6ae708d5a6cc5. 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/DEN960500802.
String Quartet No. 1 in C Minor, Op. 51 No. 1: III. Allegretto molto moderato e comodo – Un poco più animato - Recorded 2007
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4b6d4df4a65ff4ffd18d1a0ce4c7acf21b15eda68a975e3c42b0856179fe0475. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/DEN960700003.
String Quartet No. 2 in A Minor, Op. 51 No. 2: I. Allegro non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd4536509b9ad7d7b8977aad2d932d7f51b791cfeea430ef950fed28b7568f4c1. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/DEN960500791.
Piano Quintet in F Minor, Op. 34: I. Allegro non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6415cc0d33c91d9e82232464ebc8171d614feee7fe4f73ff33df973f99a9019b. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/DEN960601301.
String Quartet No. 2 in A Minor, Op. 51 No. 2: IV. Finale. Allegro non assai – Più vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8c9119cd61c5c23b02a49c2117db927384a4705bcba291a1b8d751a1aef0acea. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), 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/DEN960500794.