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 0xe9feb76aa8ba206b1eab9de47a65e905b79a58703cb2099399a653ef5820c4e9. Chain 2 (Bitcoin): anchored in block 953614 (2026-06-14T08:40:32Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/182f1a26-3251-4de5-95a8-aeceabf96e28.json and https://artists.proofprofile.net/proofs/artist/182f1a26-3251-4de5-95a8-aeceabf96e28.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Spohr: Octet, Op. 32; Poot: Octet (Vienna Octet — Complete Decca Recordings Vol. 10)
Schubert: Piano Quintet, D. 667 "Trout"; Spohr: Nonet, Op. 31 (Vienna Octet — Complete Decca Recordings Vol. 4)
Schubert: Piano Quintet, D. 667 "Trout"; Beethoven: Septet, Op. 20 (Vienna Octet — Complete Decca Recordings Vol. 12)
Mozart: Divertimento in D Major, K. 334; Divertimento in F Major, K. 247 (Vienna Octet — Complete Decca Recordings Vol. 3)
Mozart: Divertimento No. 15 in B-Flat Major, K. 287; Divertimento in E-Flat Major, K. 113 (Vienna Octet — Complete Decca Recordings Vol. 8)
Mendelssohn: Octet, Op. 20; Schubert: Octet, D. 803 (Vienna Octet — Complete Decca Recordings Vol. 2)
Kreutzer: Grand Septet, Op. 62; Beethoven: Septet, Op. 20 (Vienna Octet — Complete Decca Recordings Vol. 1)
Brahms: Clarinet Quintet, Op. 115; Mozart: Clarinet Quintet, K. 581 (Vienna Octet — Complete Decca Recordings Vol. 5)
Beethoven: Piano Quintet, Op. 16; Spohr: Octet, Op. 32 (Vienna Octet — Complete Decca Recordings Vol. 13)
Spohr: Piano Quintet; Double Quartet; Octet; Nonet
Brahms: Clarinet Quintet; Mozart: Clarinet Quintet; Baermann: Adagio
Mendelssohn: Octet; Schubert: Piano Quintet in A - "Trout"; Octet
Schubert: Octet in F / Spohr: Octet in E
Beethoven: Septet, Op. 20; Sextet, Op. 71 (New Vienna Octet; Vienna Wind Soloists — Complete Decca Recordings Vol. 8)
Schubert: Octet, D. 803; Minuet and Finale for Wind Octet, D. 72 (New Vienna Octet; Vienna Wind Soloists — Complete Decca Recordings Vol. 7)
String Sextet in A Major, Op. 48, B. 80: I. Allegro moderato
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 0x532ee4d9b7cf36bec8dc15b2b4270aa1bd665f1047f6896b6ebf2f00a3305afd. Chain 2 (Bitcoin): anchored in block 960506 (2026-08-01T03:50:58Z), 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/GBF077111401 — a six-check JSON result.
String Sextet in A Major, Op. 48, B. 80: II. Dumka. Poco allegretto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x83561f39ebc768029e6e56d250c5a0021895bf6f2af740d5a32a5a4af0dee25c. 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/GBF077111402 — a six-check JSON result.
Octet in E-Flat Major, Op. 20, MWV R20: I. Allegro moderato, ma con fuoco
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfe741381e1d10bb810981b7e3667b42cf746dd856d7a365cf373212319d38269. Chain 2 (Bitcoin): anchored in block 960334 (2026-07-31T02:19:15Z), 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/GBF077210271 — a six-check JSON result.
Octet in E-Flat Major, Op. 20, MWV R20: II. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x65f5f9d40380110145353c08f07ea5b0ec336c712accabf1c031bcdab4662c4a. Chain 2 (Bitcoin): anchored in block 960473 (2026-07-31T22:27:44Z), 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/GBF077210272 — a six-check JSON result.
Octet in E-Flat Major, Op. 20, MWV R20: IV. Presto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf1bed4eb35a3c2c4ba6465d4a9f52eb14834aa752edac27a7cf7ce7f73e7df01. 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/GBF077210274 — a six-check JSON result.
Septet in E-Flat Major, Op. 20: I. Adagio - Allegro con brio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xee989a417c1fdbff35fec0c074f01ab823b6a8fc4b11b1fb352d5607903eb81a. Chain 2 (Bitcoin): anchored in block 960473 (2026-07-31T22:27:44Z), 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/GBF075910101 — a six-check JSON result.
Mendelssohn: Octet, Op. 20; Rimsky-Korsakov: Quintet (Vienna Octet — Complete Decca Recordings Vol. 27)
Dvořák: String Sextet, Op. 48; String Quintet, Op. 97 (Vienna Octet — Complete Decca Recordings Vol. 25)
Badings: Octet, Op. 67 (Vienna Octet — Complete Decca Recordings Vol. 26)
Mendelssohn: Piano Sextet, Op. 110; Borodin: Piano Quintet (Vienna Octet — Complete Decca Recordings Vol. 21)
Piano Sextet in D Major, Op. 110, MWV Q16: I. Allegro vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x489e6d6dc468ad68b5a206297bc6398d0c7f4a531f4c67838fd78806a5dc5c69. 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/GBF076812981 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde19fc2b0e988e0237cc8bb1026653c409b80a3110b2cf80bd73c1b147fa991b. 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/GBF076812991 — a six-check JSON result.
Piano Quintet in C Minor: II. Scherzo. Allegro non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1dfb587ca3c2934e65a5b2c28d30f1942316ea3b9f36fa92e3c11597305f4b63. Chain 2 (Bitcoin): anchored in block 960478 (2026-07-31T23:30:38Z), 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/GBF076812992 — a six-check JSON result.
Kreutzer: Grand Septet; Berwald: Grand Septet (Vienna Octet — Complete Decca Recordings Vol. 22)
Dvořák: String Quintet, Op. 77; Spohr: Quintet, Op. 52 (Vienna Octet — Complete Decca Recordings Vol. 23)
Beethoven: Quintet, Op. 29; Sextet, Op. 81b (Vienna Octet — Complete Decca Recordings Vol. 24)
Spohr: Nonet, Op. 31; Double Quartet, Op. 87 (Vienna Octet — Complete Decca Recordings Vol. 20)
Mozart: Divertimento, K. 205; March, K. 290; Cassation, K. 99 (Vienna Octet — Complete Decca Recordings Vol. 18)
Britten: Sinfonietta, Op. 1; Hindemith: Octet (Vienna Octet — Complete Decca Recordings Vol. 19)
Mozart: Divertimento, K. 287; M. Haydn: Divertimento (Vienna Octet — Complete Decca Recordings Vol. 16)
Divertimento No. 15 in B-Flat Major, K. 287: III. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd56bd112cf88ca4865cc34be043106ac54fc3831018fd02612e151e324cd1f86. Chain 2 (Bitcoin): anchored in block 960487 (2026-08-01T00:15:43Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBF076212393 — a six-check JSON result.
Divertimento No. 15 in B-Flat Major, K. 287: V. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x833379569058b7129f261d245accd10e63e2608d3bf755d5115f72e6ca48d3db. 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/GBF076212395 — a six-check JSON result.
Mozart: Clarinet Quintet, K. 581; Divertimento, K. 247 (Vienna Octet — Complete Decca Recordings Vol. 17)
Clarinet Quintet in A Major, K. 581: II. Larghetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6911a85a8512b7a9060a5bbc6d64f4500126a553e11da00a1d1667e16d54d421. 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/GBF076310222 — a six-check JSON result.
Clarinet Quintet in A Major, K. 581: IV. Allegretto con variazioni
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x05bc9bcddd7498b5c7b049e5c2df274fa53b11f7ec1d6ffe3353447f5ced96cd. Chain 2 (Bitcoin): anchored in block 960500 (2026-08-01T03:13:03Z), 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/GBF076310224 — a six-check JSON result.
Mozart: Divertissements, K. 334 & K. 136 (Stereo Version)
Mozart: Divertimentos, K. 136 & 334 (Mono Version)
Mozart: Divertimento, K. 334; K. 136/125a (Vienna Octet — Complete Decca Recordings Vol. 14)
Divertimento in D Major, K. 334: IV. Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xed0dbfd955d1253f04cb7cf737460d697865502dfca60aed42d09261b2c6a642. Chain 2 (Bitcoin): anchored in block 960095 (2026-07-29T11:07:37Z), 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/GBF076110544 — a six-check JSON result.
Brahms: Clarinet Quintet, Op. 115: Baermann: Adagio for Clarinet and String Quintet (Vienna Octet — Complete Decca Recordings Vol. 15)
Schubert: Octet, D. 803 (Vienna Octet — Complete Decca Recordings Vol. 11)
Mozart: Piano Quintet, K. 452; Clarinet Trio, K. 498 "Kegelstatt" (Vienna Octet — Complete Decca Recordings Vol. 9)
Beethoven: Septet, Op. 20; Dvořák: String Quartet No. 10 (Vienna Octet — Complete Decca Recordings Vol. 7)
Octet in F Major, D. 803: IV. Thema. Andante - Var. I - VII
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x410236344dd67d278880fda12ddc4949465e13f4143f7835412e3f033d9edbe2. 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/GBF075710064 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6acbf82ef6b392308fc2cff3bef75a8c8d6b596ff581d38a9f25c0b34ba1d936. Chain 2 (Bitcoin): anchored in block 957039 (2026-07-07T12:58:18Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBF078911982 — a six-check JSON result.