thumb|right|321px|Tokyo String Quartet The were an international string quartet that operated from 1969 to 2013. History The group formed in 1969 at the Juilliard School of Music. The founding membe
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 0x106d0e2260d3830c3fd7fe68b0570802c4525587175351d3fba380cba32768d4. 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/b0870516-07d6-469a-8333-f8a66d7f4d33.json and https://artists.proofprofile.net/proofs/artist/b0870516-07d6-469a-8333-f8a66d7f4d33.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
The Tokyo String Quartet Plays Haydn and Mozart
String Quartet No. 1 in G Major, Hob. III:75: I. Allegro con spirito
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 0x5a95ec3eae3c53bee4579c58db6ae5b09fa127218b5781c88844f548d8011ade. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USSM18100980.
String Quartet No. 1 in G Major, Hob. III:75: II. Adagio sostenuto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbdcfb013e1101297497997ce804ed828f5d730b8afbdef54b1727f3e07ab5962. 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/USSM18100981.
String Quartet No. 4 in B-Flat Major, Hob. III:78 "Sunrise": II. Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2e30ae30853b04a59f7cd7faf9e33e444e31a3ed657969193bc989bb6b03a356. 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/USSM18100985.
String Quartet No. 4 in B-Flat Major, Hob. III:78 "Sunrise": III. Menuet - Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x053a4c0edf5c06fd63eb2ec470ceaebc936f8b0f17f1ca5ba9b685d40c5437ed. 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/USSM18100986.
String Quartet No. 1 in G Major, Hob. III:75: III. Menuet. Presto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc180067670785db58928752fdb0fe80f3d124511f8285eb275e521bc407f599e. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USSM18100982.
String Quartet No. 1 in G Major, Hob. III:75: IV. Finale. Allegro ma non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfd8e4a5942ddc08f37d7e4ddea9f9582bdc17adee0dc1c7a387d06a1937af1e6. 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/USSM18100983.
String Quartet No. 4 in B-Flat Major, Hob. III:78 "Sunrise": IV. Finale - Allegro ma non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2bf4ac8763f75daf7474a3d6d7d299a1fc81d5abcabe6aa98224817c349e7bcf. 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/USSM18100987.
String Quartet No. 5 in D Major, Hob. III:79: I. Allegretto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbebdf0439946f1fbc44e2215a057df752bbce7d224910560a25546e682a66ead. Chain 2 (Bitcoin): anchored in block 960448 (2026-07-31T18:48:12Z), 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/USSM18100988.
String Quartet No. 2 in D Minor, Hob. III:76 "Fifths": I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5f865946408fb5e08c91ca750a28c106c8ff3c0639e98fb054337355dc5fb810. Chain 2 (Bitcoin): anchored in block 960241 (2026-07-30T09:58:01Z), 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/USSM17900648.
String Quartet No. 5 in D Major, Hob. III:79: II. Largo cantabile e mesto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdc302c08092bd92935a857c3f2c23ae18366d88c7e922ff19941d6ab702bbb63. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/USSM18100989.
String Quartet No. 2 in D Minor, Hob. III:76 "Fifths": II. Andante o piu tosto allegretto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xab128c318f6412d3bfd8f1de91baa36ff28a9ec73282a6b12372770152b054ac. Chain 2 (Bitcoin): anchored in block 960383 (2026-07-31T09:50:37Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USSM17900649.
String Quartet No. 2 in D Minor, Hob. III:76 "Fifths": III. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd32fe5ca006acf4cc0228da29fd7c4b856ce636492390047270ca514ef8e5f39. Chain 2 (Bitcoin): anchored in block 960305 (2026-07-30T20:14:59Z), 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/USSM17900650.
String Quartet No. 5 in D Major, Hob. III:79: III. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x388139ce806227ad13f392cd4e29fb549ca7f628a6f2959b37a0e7f833939f74. 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/USSM18100990.
String Quartet No. 2 in D Minor, Hob. III:76 "Fifths": IV. Finale - Vivace assai
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe49fdc044e41c2cf423e5d10f24c9f3eb3453e91747550cf833b62e437e927cd. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USSM17900651.
String Quartet No. 5 in D Major, Hob. III:79: IV. Finale - Presto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8030c5e04d529824d5261e979f054ccdc1db3b3ae8bb229366ce0705c3bb216e. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USSM18100991.
String Quartet No. 6 in E-Flat Major, Hob. III:80: I. Allegretto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf522e26aae8ce6ec08f26f56acd9acde8e289b8eaa3b3b1f14bacde4e181033c. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/USSM18100992.
String Quartet No. 3 in C Major, Hob. III:77 "Emperor": I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa3bc42ff373feaeef6a8bea9ea1e5962ef3f74a21b56cc2fd096541b70b1cb05. 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/USSM17800601.
String Quartet No. 3 in C Major, Hob. III:77 "Emperor": II. Poco Adagio - Cantabile
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfcc7ae1699ca09bdc3bd31324f6bce31bc7d031639991e450892dffe05aff07d. Chain 2 (Bitcoin): anchored in block 960403 (2026-07-31T13:04:34Z), 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/USSM17800602.
String Quartet No. 3 in C Major, Hob. III:77 "Emperor": III. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x18a29824b84c56bb9e30a509f4d51fe5dcd383a76b92c36147fc7b9f56007743. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/USSM17800603.
String Quartet No. 6 in E-Flat Major, Hob. III:80: III. Menuetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9de5070483d1d1dc445e885c4adc0ea8ec977b51109f8c2699c86ca48d2c457d. 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/USSM18100994.
String Quartet No. 3 in C Major, Hob. III:77 "Emperor": IV. Finale - Vivace assai
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x56e4ede3ead0622d3658b285aa23bf121efc87f77b2fd5afe7902ecde827963e. Chain 2 (Bitcoin): anchored in block 960240 (2026-07-30T09:57:33Z), 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/USSM17800604.
String Quartet No. 6 in E-Flat Major, Hob. III:80: IV. Finale - Allegro spirituoso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x513c42c0cd9bedf2d91f98b86dfa02da00d4c4b59be2a2997e538622b9be71cd. 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/USSM18100995.
Brahms: Complete String Quartets - Schubert: String Quartets Nos. 12 & 14
Dvořák: Quartet No.12 - Smetana: Quartet No.1
String Quartet, No. 13 in B-Flat Major, Op. 130: V. Cavatina: Adagio molto espressivo
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Quintet for Clarinet and String Quartet in A Major, K. 581: I. Allegro
Mozart: Clarinet Concerto in A Major, K. 622 & Clarinet Quintet in A Major, K. 581
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