thumb|right|Sisask in 2011 thumb|right|Estonian TV Girls' Choir with Urmas Sisask at St Paul's cathedral in London, 2008. Urmas Sisask (9 September 1960 – 17 December 2022) was an Estonian composer.
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 0x5220ffc040a14dcabe779737ed3d2a7354c6ad293c43c7608c9edbc95a59086b. 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/0900a52e-164e-4c8f-a25e-489327715256.json and https://artists.proofprofile.net/proofs/artist/0900a52e-164e-4c8f-a25e-489327715256.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Tapiola Originals - Choral Works Commissioned by the Tapiola Chamber Choir
Lighten mine eyes – Contemporary Choral Music
International Orange Chorale of San Francisco
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 0xb2c94cb32c551f3294047556856c5419113014cc0e40e0afa51f69c0a852022a. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/USCGH2173396.
2014 American Choral Directors Association, Western Division (ACDA): Mt. San Antonio College Chamber Singers & Salt Lake Vocal Artists [Live]
Baltic Exchange: Prauliņš - Missa Rigensis and Other Choral Works
Latviešu, Lietuviešu un Igauņu Kora Mūzika
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa39c514de531d34e8fa1d9e0614c6148bcfcdb3ee4921d802582cf3313348565. Chain 2 (Bitcoin): anchored in block 959146 (2026-07-22T18:05:20Z), 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/SEYOK1960350.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2561d34ba121bd5f052be1629838051ce224db87aae392f84a2ab0ac2b2543f8. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/SEYOK1960355.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x011ca1f2d4a049c44835c34f431839d54907f6202042d194ccc682575dc96ed5. Chain 2 (Bitcoin): anchored in block 957819 (2026-07-21T17:30:53Z), 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/SEYOK1960357.
Northern Lights Vol. 2 - Music of Contemplation for a New Age [US Version]
2014 American Choral Directors Association, Western Division (ACDA): University of Southern California Thornton School of Music Chamber Singers & Riverside City College Chamber Singers [Live]
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6924fe5d439d8cb25d800a5be42ec7b23686ea00a6840e0a310678dc3fee2a5f. 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/USVZX1407810.
4 Shakespeare Songs: No. 1. Come Away Death
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9cab98de29c9c921246b03756e98dca0e2ffdc22e2fda6fe17a38a5d19f98081. 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/SEVWU0300213.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8e7fddc0f5023cd76e36029df3fb7dee0dc113d04723068fd38ac0cfab765e14. 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/SEVWU0300214.
4 Shakespeare Songs: No. 3. Double, double toil and Trouble
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5d6fb788e34868ad6c1352c16e17bd3e5c1d61fb3feaee69d30b75fb243e48d0. 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/SEVWU0300215.
4 Shakespeare Songs: No. 4. Full fathom five
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x05d3c91a83a9b62ea1d078d848385e349f61cded173571553df0ad34cf6f4661. Chain 2 (Bitcoin): anchored in block 957819 (2026-07-13T07:53:33Z), 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/SEVWU0300216.
Deutscher Jugendkammerchor: Nachtschichten
Urmas Sisask: Starry Sky Cycle: Equatorial Sky
Gloria Patri... (1988 15 meditative and tranquil hymns for mixed choir a cappella)
Urmas Sisask : Gloria Patri..., Magnificat
Sisask : Gloria Patri... 24 Hymns for Mixed Choir : V Laudate Dominum
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb67f136f3514108979d03327a140ec6aa97ed17b002d734be669fa2071b04da7. Chain 2 (Bitcoin): anchored in block 956889 (2026-07-06T06:56:49Z), 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/FIFIN9301005.
Sisask : Gloria Patri... 24 Hymns for Mixed Choir : XVII Dominus vobiscum
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9bd6a9211ed7bd85542857912fd53b8aa3da8089f7967b2b1ff263aad0f28b4b. 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/FIFIN9301017.
Sisask : Starry Sky Cycle Op.52 - Pleiades : 17. II Maja
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x855f48200e1fa9a731d8e3d8ccdd79eb9bc31b2fcfd38d18d7f05964c916b130. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/FIFIN9300417.
Sisask : Starry Sky Cycle Op.52 : 25. Ursa Minor [Peace]
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x831541f9c430f3d913828b0a307c5cbb7e5bd952ac051f29d952bde5fabaeac7. 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/FIFIN9300425.
7 Part Cycle The Star Of Bethlehem Capella, Op 56
Sisask: Jõuluoratoorium (Weihnachtsoratorium), Missa No. 4 Jõulumissa (Weihnachtsmesse)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4d6da832504c30dec57d254dc7b494f2ad0139381dde144360c9b80bede799ec. Chain 2 (Bitcoin): anchored in block 959137 (2026-07-22T14:03:35Z), 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/DEB379402270.
MU ISAMAA ON MINU ARM / MY HOMELAND IS ALL MY JOY
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x217d877a4b318ee345628cb79caf0c100c7f0604816d046619501a169d5e64d6. 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/DEB379402290.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6036e604fb8829179790437d04c4a723335eeffe3bab8bbfc60ecb68085c757a. 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/LTA201400017.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe03f167bbcdcd04bdc844716b644dbe544252eb0d771ea3718de0e918b454b8e. 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/DEAQ70501005.
Northern Lights - Music From Scandinavia
Tallis - Sisask - Świder - Palestrina - Szymanowski - Rachmaninow
Peace - Music For Reflection And Consolation