Quink is a Dutch vocal ensemble founded in 1978. The five singer line-up c. 1996 included Machteld Van Woerden (soprano), Kees-Jan De Koning (bass), Harry Van Berne (tenor), Corrie Pronk (alto), Marj
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 0xf7c0261712e1e44ec818728b9518db3c3eb65ae4ba50362ef781127a7901f716. Chain 2 (Bitcoin): anchored in block 954549 (2026-06-20T10:56:20Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a757e257-2503-4a62-91e4-a93c60a936cf.json and https://artists.proofprofile.net/proofs/artist/a757e257-2503-4a62-91e4-a93c60a936cf.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Manneke: Pneoo - Archipel I - Pseaume 121 - Organum - Threni - Et in tempore vesperi erit lux
Three Elizabethan Partsongs: I. Sweet Day
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 0x8c2a37fab08ce29116a83e5e97c398430f245532dcd31c5795315c574d4f5842. Chain 2 (Bitcoin): anchored in block 956894 (2026-07-06T07:53:57Z), 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/NLY331505060 — a six-check JSON result.
Three Elizabethan Partsongs: II. The Willow Song
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x002d8e3a2caa0f5f3686c016065af87eb15577546b4e8848d8c56ee1e1051c53. 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/NLY331505061 — a six-check JSON result.
Three Elizabethan Partsongs: III. O Mistress Mine
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x11b9161f170c5cb5e3225db024b34e2737dcf77e7b78d0ef41f37c8f8e2ca8a1. Chain 2 (Bitcoin): anchored in block 960229 (2026-07-30T08:30:10Z), 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/NLY331505062 — a six-check JSON result.
6 Modern Lyrics: VI. Music, When Soft Voices Die
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x38ea491a13126bc2c15252cfbb0c21fb39c3d440fc34feca6403df1ef28bd2dc. 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/NLY331505084 — a six-check JSON result.
Vasquez: Gentil señora mia, 16th Century Songs and Villancicos
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde27ff2a218fc11a81a4031c5eb7ebd2e9c49de351e4daefafc351a0f37f2ed6. 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/NLB151100329 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x753f9a18f724dabb60d8e6ee78ec87fe201d1f106266e3f326e093b920c6a5bb. 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/NLB151100331 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4de5bb048685e79c5f0c95709d2cbd6952dba45c6bd0be51b440b6109cedcb3b. 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/NLB151100335 — a six-check JSON result.
Seven poems of Robert Bridges: I praise the tender flower
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x20be39016941347df807216a6f492b029d0e2a39ba23a38fe040053e3eb03c0c. Chain 2 (Bitcoin): anchored in block 960429 (2026-07-31T16:07:24Z), 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/NLB151100342 — a six-check JSON result.
A Un Niño Llorando - Christmas with Quink Vocal Ensemble
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa3818ff6def702fc50c9228399d39654bd75947ea90b5e6f3b48f8dedd6fe39a. 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/NLB150800478 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x886fb1a474825d866789245cb36edb64bed1eca9e054a5a5d2ff695885610169. Chain 2 (Bitcoin): anchored in block 960273 (2026-07-30T15:42:38Z), 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/NLB150600046 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x64f6f942bfb84715ca428f6f8749a061e4aa26073a3d16bc68a1c6f316541eb5. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLB150600047 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x215c742a6065affd127450374ac00c3defc149ccf3697a625697ca7ea2ed2bac. 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/NLB150600055 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x694650ffb93f2f0d79950c15ee25333d345d57a1e33a1a79f6c31ad927c834cc. 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/NLB150600053 — a six-check JSON result.
Invisible Cities: Contemporary A Cappella Music
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc24eebdd6889b0d853229b9019c0a5725a282331eb53c7bab9d0d98fe067ad19. Chain 2 (Bitcoin): anchored in block 960468 (2026-07-31T21:25:57Z), 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/USTE10401384 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ecc22c8c2651cb48b19bda3193de51b6beae96ba953cd639345b4d59a51000a. Chain 2 (Bitcoin): anchored in block 960229 (2026-07-30T08:30:10Z), 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/USTE10312328 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8a6ab17c4155fbedc8683fdde295e2b3bbc9713f0386d24447ca78a03802e42b. Chain 2 (Bitcoin): anchored in block 960376 (2026-07-31T09:09:19Z), 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/USTE10317328 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5678dda8d102da67dd3f3fa21967c102568d70f9b3fcd2ee9565ab4426808c6b. 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/USTE10401275 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x59affbd188817d7baed9b242653a0de4bb71443cdd2f70f3553a1104400f28ba. Chain 2 (Bitcoin): anchored in block 960273 (2026-07-30T15:42:38Z), 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/USTE10403275 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xabbf9bc31aaadaac646e3826d1a7c100511f79e46db168b61e8d3e2b97d21ed5. 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/USTE10405275 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdfc6942e531dd28e82a1879c7b78454ca1b1429873137cfade713696cf802c02. 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/USTE10420275 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x62fea36362dc808fe4393de02fa569f09a9e0fe72a07cbcf686c02246087acfd. 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/USTE10425275 — a six-check JSON result.
William Byrd, Mass for four voices, Choral Music
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2533f08cdf5815d778a064a6a10ba764b5ca67078939e8de922c747113b98513. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR0O70720120 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x92d6f71b6dfc1cd17fcf566c9b2240412c80ad2640881a88d93fb8184a0b8665. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR0O70720130 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc904b53c1b12511a8bf35fd8d902d535fbcfa8addf5456460f71f79e58a94ad7. 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/FR0O70720150 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x97b26a8afa33cb9b0f10dae0b2157a3bb28b6f88a8765afae41a5d3e05892c97. Chain 2 (Bitcoin): anchored in block 960494 (2026-08-01T01:44:32Z), 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/FR0O70720160 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcd67224dc79ae901262b90e4193deb0457d8ac18d433daea1bc421abea620282. Chain 2 (Bitcoin): anchored in block 960268 (2026-07-30T14:53:07Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR0O70720170 — a six-check JSON result.
Benjamin Britten, Hymn to St Cecilia, Sacred and Profane
Diepenbrock: Anniversary Edition, Vol. 7: Works for Choir a cappella
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x870a3e217e028064ba2ce5b95d6bd1bfefe4cd41841d4eb5975acce0a6199973. Chain 2 (Bitcoin): anchored in block 960273 (2026-07-30T15:42:38Z), 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/NLQ661200138 — a six-check JSON result.