Leevi Antti Madetoja (; 17 February 1887 – 6 October 1947) was a Finnish composer, music critic, conductor, and teacher of the late-Romantic and early-modern periods. He is widely recognized as one of
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 0x9b977d0e631ecffa11e4daa8ddd28a52a443fc6d7202061db8816f368edb1fb0. Chain 2 (Bitcoin): anchored in block 953812 (2026-06-15T17:06:52Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f5573dea-8d72-44d4-b5bf-9fecda12f981.json and https://artists.proofprofile.net/proofs/artist/f5573dea-8d72-44d4-b5bf-9fecda12f981.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Madetoja: Symphonies Nos. 1 and 3 & Okon Fuoko Suite
Madetoja : Valkeat kaupungit Op.8 No.5 [White Cities]
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 0xe5457cbf85664040d2e2eb6491388d7800a54687fadfa08dee9102b4b8140c82. 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/FIFIN9000081.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8ce32a43e23198fb1d1cebbf425c902442daf2470e41edd5f96a951cb4399b6c. 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/FIFIN9500389.
Madetoja : An Old Memory, Op. 31 No. 4 (Vanha muisto)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x310114d5f4904f8eae00ca0449cef9ba9823f2b425c03c19536abe3415e841c3. Chain 2 (Bitcoin): anchored in block 960506 (2026-08-01T03:50:58Z), 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/FIFIN9200059.
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