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 0x1b4ad841135fdd62b283925b90b9abfe00fb512cf4057d7748e7c26901f1b969. Chain 2 (Bitcoin): anchored in block 953754 (2026-06-15T06:45:19Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/af2edd2b-fed3-4dfb-a724-ac35d6065240.json and https://artists.proofprofile.net/proofs/artist/af2edd2b-fed3-4dfb-a724-ac35d6065240.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 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 0x90449010dde12c925140a0c0bccf17a966b35d3631a3530078e62f5ada48b99c. Chain 2 (Bitcoin): anchored in block 960455 (2026-07-31T19:53:13Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QMDA72151611.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x746185d591b0eb51e2cef5b9c18cb9b300d50f352c10bb3aae801490061459e7. Chain 2 (Bitcoin): anchored in block 960489 (2026-08-01T00:40:43Z), 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/QMDA72151615.
Violin Concerto No. 4 In D Major Kv 218: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd37a3ec9a0757ebcb1c213a39a2afb34ffef43dc1d0d20082caf2e9c38327d2b. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NOMPP0606010.
Sonate In D-Dur Für Zwei Klaviere Kv 448: I. Allegro con spirito
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x20f1ff34b8f2aa1f82f3baee9e0ba528eb1aafecabba574a59730b5c9c2dcbf2. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NOMPP0809010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8bd73fa119b99e9e2f444429b5546119832c430d94de60b6cb273af98dc6becf. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NOMPP0702010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4b5d20f715f511d961739ab6c57c287bfb67140bd7e344f5296882bb2ef4f0bc. 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/NOMPP0701200.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x47815749efc738f8d27eea8a624ccdd8a9f18008c7be52e7dc4f5d1a1c02720b. Chain 2 (Bitcoin): anchored in block 960340 (2026-07-31T03:15:04Z), 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/NOMPP0604100.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x49aa9986d8f326c3ee9ca18cb82c5b68158a7f813594325a4772ec48dc1c0011. 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/NOMPP0708140.
Recitative And Aria From Cantata Rv 679, Che Giova Il Sospirar, Povero Core
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfb239e643cc737a1ae018fd499aaca0478f3e9d92960498de1161300ce0551b1. 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/NOMPP0808010.
String Quartet In D, Op. 76, No. 5 - Finale - Presto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde726fa4154dfaddab6c78ffbd460ae3b0df681f8df1b3543b30d9e55cea354a. 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/NOMPP0805040.
Mustonen: String Quartet No. 1 & Piano Quintet
Mozart: String Quartets - Dedicated to Haydn, Vol. 2
Schumann: Piano Quintet, Op. 44 / Piano Quartet, Op. 47
Piano Quintet, Op. 44: I. Allegro brillante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaf0b3af8afe05670b66ab0c70c73e9db4aba574ccf39a4bb660a65dc423e0f1f. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NOEHX1920010.
Piano Quintet, Op. 44: II. In modo d'una Marcia. Un poco largamente
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xaf0a46e93bfca56b1d8c4376d237c6f27ea0691104d5ceeac437d97d6bb83657. Chain 2 (Bitcoin): anchored in block 960321 (2026-07-30T22:27:30Z), 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/NOEHX1920020.
Piano Quintet, Op. 44: III. Scherzo. Molto vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfce96ea020543cd34436bedb8f57a17233f3e2ff7261b2254e9da2bb385e3b8d. Chain 2 (Bitcoin): anchored in block 957122 (2026-07-08T03:39:04Z), 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/NOEHX1920030.
Piano Quintet, Op. 44: IV. Finale. Allegro, ma non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1b13cdc75de082622063e7e0a133da9f39881d22189c27bc832b98dc37f6f4aa. 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/NOEHX1920040.
Piano Quartet, Op. 47: I. Sostenuto assai. Allegro, ma non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdba7ad56fc37f71c6643b2fb5f547b1e462f92755cff232ecba1bd53b80c2ba0. 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/NOEHX1920050.
Piano Quartet, Op. 47: II. Scherzo. Molto vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5b2588182349699a35ebd1b727d612ec2552fc6daaa54fc0050625d530d9c22d. Chain 2 (Bitcoin): anchored in block 960427 (2026-07-31T15:59:18Z), 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/NOEHX1920060.
Piano Quartet, Op. 47: III. Andante cantabile
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0ddb4e996887abde7b21d4c364865c30d2ef47e1ab3112e7a5d851b8123f7751. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NOEHX1920070.
Mozart: String Quartets - Dedicated to Haydn - K. 421, K. 428, K. 465
Grieg, Thommessen & Sibelius: String Quartets
String Quartet No. 1 in G Minor, Op. 27: II. Romanze. Andantino
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x296e5bad3a48bc174a04b0ae4596794c22671b042ab7b5c85c50d5239fc3219f. Chain 2 (Bitcoin): anchored in block 960314 (2026-07-30T21:00:46Z), 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/SEAEW1501020.
String Quartets, Vol. 4: Schubert-Ratkje-Britten-Haydn
Schubert String Quartet No. 13 in A minor D. 804, Op. 29, Rosamunde: I. Allegro ma non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8f8f153c53a27848aa04e682a67d6efc11a23ec0e803908f3f9b6b986ec54a22. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NOMPP1406010.
String Quartets Vol. III Haydn - Nordheim - Bartok
String Quartets, Vol. 2 Beethoven - Nordheim - Bartok
String Quartets Vol. I Haydn - Solberg - Grieg
Divertimento in B-Flat Major, K. 137: II. Andante
Divertimento in D Major, K. 136: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x41a057f7a5b2d9c2bfffb28262016a2af3c91a472e84f30fc65bc68bbfc8fbcf. 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/NOEHX2425010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x70690a97035f8497c912e87355fe9eeb87a2916ac33e6fe8122a390d73ab4319. 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/NOEHX2442010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b4c57db6068edcb474ac2d8ab659e7ad1092d819e6393df65503dca01da5ae9. Chain 2 (Bitcoin): anchored in block 960266 (2026-07-30T14:44:50Z), 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/NOEHX2432010.
Bruremarsj frå Eide (arr. for string quartet by Bjørn Andor Drage)
Haugelåt (arr. by Nils Anders Mortensen for string quartet)
En smuk aftensang (arr. for string quartet by Bjørn Andor Drage)
Skotsk fra Lom (arr. for string quartet by the Engegård Quartet)
Joik Suite (Arr. for String Quartet by the Engegård Quartet)
String Quartet No. 2, Op. 27: IV. Epilog
String Quartet No. 1, Op. 11: I. Allegro
String Quartet No. 1: IV. Impetuoso, con passione e molto rubato (quasi senza tempo) – Con fuoco all’Ungharese
Piano Quintet: II. Quasi una passacaglia