Marko Letonja (born 12 August 1961) is a Slovenian conductor. Biography Letonja studied piano and conducting at the Academy of Music in Ljubljana, where his conducting teachers included Anton Nanut.
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 0xe50bfd5d35789fbddf712ad4112e18682fc21ec1b5ba4ce98cbe59d44cf48db8. 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/01c42e3b-8d90-42a7-b223-86ceda373536.json and https://artists.proofprofile.net/proofs/artist/01c42e3b-8d90-42a7-b223-86ceda373536.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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 0xee72ba3bcbd71f7876bb11e4b0db89f5a3e5c1ec582615f7dc0e7d9630231cce. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/AUAB01650793.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e0b1a7f2e4a43e39bc9562a86f1089acb410d3975244a3cf19509f4c0893165. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/AUAB01650794.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2c5f1f9b1d88c64b8941ecbc75daa89575cac82a68a4b05128a6cc11897e83d3. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/AUAB01650795.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeb05b4082ccf89f8981103603c42d425a37d5b54aea31e3dc7eda0ff52036bd2. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/AUAB01650796.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1518363b6a0b7ff2e284991ec9df884235691f49f9b7f4c52da94998b20e06e2. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/AUAB01650797.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x23046f32d27710fa2ab0aa9adca03860ab5c7dc4b5a4116420e20db3ff8ac1c4. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/AUAB01650798.
Giuditta, Act IV: Mein Lippen, sie küssen so heiß
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf8878fb832ce51f35b3ca7ad75feb0b2bc5d43cc0c45b97a4e7a64ec76256781. 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/AUAB01650799.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2391754f03157bdbfca62ea6b1e1c9bd496269de96f66d3e59fc6744f5a42f3d. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/AUAB01650801.
Die Fledermaus, Act II: Mein Herr Marquis (Adele's Laughing Song)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x871506410b61a5ac8bb2cdee681e7977dd2dd18f44b55225a6ec82fbba7681c8. Chain 2 (Bitcoin): anchored in block 956349 (2026-07-02T11:34:59Z), 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/AUAB01650802.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcb067bb278940141195bb441bdf4baf37f117fa4f5e71bd565688f90150581e9. Chain 2 (Bitcoin): anchored in block 953513 (2026-06-13T12:47:07Z), 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/AUAB01650803.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3345a88b1733f1188bcaab03f663c9888b22ed56bf07cf1d78d6f82ec9812cd3. Chain 2 (Bitcoin): anchored in block 960207 (2026-07-30T04:47:22Z), 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/AUAB01650800.
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