thumb|Claire Barnett-Jones winning round 4 of the 2021 BBC Cardiff Singer of the World competition. She went onto also win the Dame Joan Sutherland Audience Prize Claire Barnett-Jones (born 1990) is
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 0x88d643a911693581439b895d017504de3eb13f3c3e9c962ff213fc0cb528036b. Chain 2 (Bitcoin): anchored in block 954027 (2026-06-17T00:55:08Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/39c1ad37-0927-47f1-846e-d4b9cbe8d3f0.json and https://artists.proofprofile.net/proofs/artist/39c1ad37-0927-47f1-846e-d4b9cbe8d3f0.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Katya Kabanova, JW I/8, Act I Scene 1: Introduction
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 0x715a7b1db9f556fee432764d79f349e7815a03221a01db87cb9532d78133d09a. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338901 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 1: "Vida, chvástala jsi se"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5eeb53bd881092f637ea1c7b0c3bb7b05c6e8c5258a3159e267ff5411bcf7db6. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338913 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 1: "Zázrak!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x296173a3d353f72d34fd5bdf0e9f85d3af2d31e85c18edb5cfa96796bbaf1537. Chain 2 (Bitcoin): anchored in block 960187 (2026-07-30T01:34:28Z), 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/GBDGQ2338902 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 1: "Půjdu též se projít"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x15161c68369b3a6a6a6586289a6a326850b5af14ebadba9ef2170a19e743365c. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338914 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 1: "Přišel jsi sem lelky chytat?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x465a04b331786c3d753229f0d5e98d5a65b64bc704f9058d6c157c2127163650. Chain 2 (Bitcoin): anchored in block 960181 (2026-07-30T00:53:20Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338903 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 1: "Nic zvláštního, jenom jsem trochu nachmelen"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd015dea2d2cf2dcc27122e26940aa01d1d4d7578289cef98c5bb5a204ba895f0. Chain 2 (Bitcoin): anchored in block 960258 (2026-07-30T12:45:34Z), 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/GBDGQ2338915 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 1: "Je baryňa doma?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x59b03eb4991a84caf227a9548324089cfa253199080f5426431c158b2b47e8f0. Chain 2 (Bitcoin): anchored in block 957075 (2026-07-07T18:50:38Z), 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/GBDGQ2338904 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 2: Introduction
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf016712e2d3f417af1aa35fd06c8f092b90f60f4b7f3c1c00d0e57a8f2939c8c. Chain 2 (Bitcoin): anchored in block 960291 (2026-07-30T18:23:33Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338916 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 1: "Co pak je?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x60eed8287beeb9d27c22b2707ba48665654d33d5a62ec7b485ab6ee16a52625d. Chain 2 (Bitcoin): anchored in block 960203 (2026-07-30T03:35:13Z), 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/GBDGQ2338905 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 2: "Nikoho tu není!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcfe7cd917c6839ee381154e44fb4c5743caf96fe2d4660446d2a04efebae9fe5. Chain 2 (Bitcoin): anchored in block 960317 (2026-07-30T21:35:24Z), 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/GBDGQ2338917 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 1: "A potom běž domů"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9bc35e186b27110e494388d786949c30c7fe6a35dde12487fa7313db1fd840bd. Chain 2 (Bitcoin): anchored in block 960231 (2026-07-30T08:33:28Z), 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/GBDGQ2338906 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 2: "Za vodou, za vodičkou"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x892cffc1e89df5465816f4a89f6be824b0b1bc5eee7b23aec289cad8726ccf45. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338918 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 1: Intermezzo I
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x09292b73955c356c35cee763bab7791044c7b9332a4c794634a5979820a8fe87. Chain 2 (Bitcoin): anchored in block 960236 (2026-07-30T09:37:10Z), 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/GBDGQ2338907 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 2: "Jste to vy, Katěrino Petrovno?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa520ab1903ad460b601f89c5e895f685c510e2ed323c59ab2db8358f17cd580d. 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/GBDGQ2338919 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 2: "Víš co mi napadlo?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5587a45554b90b2667c813978735703c80473f500863bae3a0fec4fab166c2ed. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338908 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 2: "Nuže, shodli jste se?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4f6f77db6ace4b946919057d5f325b02fbff9f0ac3059a4a87d02d61d44e7d83. Chain 2 (Bitcoin): anchored in block 960435 (2026-07-31T16:33:26Z), 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/GBDGQ2338920 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 2: "Zdráva..."
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x91c101571efec014d49cca45adbd12e0f37dbbb5b5b14e3275ed2d451f525eb9. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338909 — a six-check JSON result.
Katya Kabanova, JW I/8, Act II Scene 2: "Choď si, dívka, do času"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcc4bdb4cf5e184ce390cc8d8c99df8062765391689171652512c8fbea926a04e. Chain 2 (Bitcoin): anchored in block 960209 (2026-07-30T05:15:54Z), 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/GBDGQ2338921 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 2: "Ale nač tobě to vykládám?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x85bffef58f111ea08933b21c4680f032b05a99c67564cf6e8664db3316fdde71. Chain 2 (Bitcoin): anchored in block 960209 (2026-07-30T05:15:54Z), 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/GBDGQ2338910 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 1: Introduction - "Krápe!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb72bb626552f3b3e2d99db4b439517608b0bae07b2ee46d2248cc0edcb806398. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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/GBDGQ2338922 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 2: "Což pak už mne nemáš rád?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x65b72d4e55a4535f9dc19a4abf57f452b046651f968c573c657400262a345d49. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338911 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 1: "Celého mne to pokropilo"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3296133cb1e92e0a4380af842dd1346fc92bda628d0f32ee504ebaf89a191f19. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338923 — a six-check JSON result.
Katya Kabanova, JW I/8, Act I Scene 2: "Abych ani otce"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf17f6c02cb7faf9ba74e854222a2660477d3ffaffc28ac9b64ac3ab30a561e11. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338912 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 1: "Pssst! Pssst! Zdá se, že je to on!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x198f793902f8b20febae07218e96a08877f4ecc6c86aeafaca7bd4689738e609. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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/GBDGQ2338924 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 1: "Tu jdou! Maminka jde s nimi!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x261f1081b88207f764cef60c0c38bf0c90645171552db3669a34515a94e336ec. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/GBDGQ2338925 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 2: "Ach Glašo!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcc801c5f59a3f025c01e80dcb10bd8e431199066cf48d96a85d6dff1e29b975f. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338926 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 2: "Vidět se s ním"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xda0d207da6a80102b9a294e323e786986ac002a1f8688f1359d24d5c774e8a38. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338927 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 2: "Proč se tak chovají?"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbd5fa558ecb4e281bb645fa3f3d4ffb537af216341eaf591e8bff5089bfe434b. Chain 2 (Bitcoin): anchored in block 960370 (2026-07-31T08:38:45Z), 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/GBDGQ2338928 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 2: "Ale smrt nepřichází"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x57b6dc1126a4a17f786d26978bb71fa2816c41bf6ac6d739a408cb0b43b78157. Chain 2 (Bitcoin): anchored in block 960327 (2026-07-31T00:26:26Z), 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/GBDGQ2338929 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 2: "Svedl nás Bůh!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b1be285eb5b48f6852c9aa90b826a178b2689bae7934f50b16ef2cdc45c82b4. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/GBDGQ2338930 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 2: "Ale ne!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcce4e77b150b73f92fa2c07b6ba2a777b3a95d8b2e65639c254fbb2e3ebfb482. Chain 2 (Bitcoin): anchored in block 960362 (2026-07-31T06:58:00Z), 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/GBDGQ2338931 — a six-check JSON result.
Katya Kabanova, JW I/8, Act III Scene 2: "Ptáčci přiletí na mohylu"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x86281ecfacf5073e2c454601a1bde4de79f0d23cb5abf6c07be3ae488a5e9650. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBDGQ2338932 — a six-check JSON result.
Strauss: Ariadne auf Naxos (Edinburgh International Festival)
The Jade Mountain – Songs by Edmund Rubbra
Rubbra: The Jade Mountain, Op. 116: I. A Night Thought on Terrace Tower
Rubbra: Two Sonnets by William Alabaster, Op. 87: I. Upon the Crucifix
Rubbra: Orpheus with his lute, Op. 8 No. 2