Josef Casimir Hofmann (originally Józef Kazimierz Hofmann; January 20, 1876February 16, 1957) was a Polish-American pianist, composer, music teacher, and inventor. Childhood Josef Hofmann was born in
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 0x8f018d5aa66651c9f6135db8458065fcd198446aaf46b3cf0a34cb5b6054488a. Chain 2 (Bitcoin): anchored in block 953598 (2026-06-14T06:40:11Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0d6ca901-bbef-4e30-9ca1-7d928079d72e.json and https://artists.proofprofile.net/proofs/artist/0d6ca901-bbef-4e30-9ca1-7d928079d72e.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Homage to Godowsky: Piano Works Dedicated to Leopold Godowsky
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 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 0x664a4c625e5104a53feae1884f1bbeb71974e1e3bf5e267e4cb67bd3a6e64b5a. Chain 2 (Bitcoin): anchored in block 960418 (2026-07-31T15:20:15Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBAJY2031001 — a six-check JSON result.
Melodia appassionata in E Minor, Op. 81 No. 6
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfcdc74d4dc2f8fdacc99a711d55de36e3f827166a5a2a1bc0a5f5208973575a9. Chain 2 (Bitcoin): anchored in block 960330 (2026-07-31T00:58:21Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBAJY2031020 — a six-check JSON result.
Fantasie. Heritage Piano Works of Bach and Chopin
"101 Classical Discoveries": An Old Tale
Spanish Romance, Op. 74 - The Smuggler (Arr. For Solo Piano by Carl Tausig) - Duo-Art 7072
Marble Halls. Piano Revelations from the Golden Age
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x288a131d7e93ba28fea451cc69890bd0808bdcd36620b1b4e0e57ade56fced60. Chain 2 (Bitcoin): anchored in block 960337 (2026-07-31T02:51:48Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEPI82321589 — a six-check JSON result.
Chopin: Œuvres pour piano - La discothèque idéale de Diapason, Vol. 2
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x117c6b2feca07c07e3708bdf3f99fa1d8a47474c099ac523133eae7de9dc33a8. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR9W13800019 — a six-check JSON result.
Piano Sonata No. 14, Op. 27 No. 2 Quasi Una Fantasia: II. Allegretto - Duo-Art 6102
Les Sylvains. Piano Evocations from the Golden Age
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x53a1f24ffe12bdedc0f3f1f84bfad8fe667153f6f8e606df612929b3e2256110. Chain 2 (Bitcoin): anchored in block 960509 (2026-08-01T04:30:37Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEPI82439070 — a six-check JSON result.
Caprice Espagnole. Piano Evocations from the Golden Age
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5ce4e62904311a6551052fca3d824d86120bcfafa38a3272230a1e16988f49d9. Chain 2 (Bitcoin): anchored in block 960389 (2026-07-31T10:20:10Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEPI82304753 — a six-check JSON result.