The Martinů Quartet () is a Czech string quartet ensemble founded in 1976, originally under the name Havlák Quartet by students of Professor Viktor Moučka at the Prague Conservatory. In 1985, with the
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 0xaa7ffcf98d3f1e5f31ea8eb01d35e55dd99e922ff7fd7b8c6e4873ce83d71289. 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/e9ccef2e-c654-4720-af60-ff570afdf7b3.json and https://artists.proofprofile.net/proofs/artist/e9ccef2e-c654-4720-af60-ff570afdf7b3.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Kalabis, Lucký Svatoš: Week of New Production 1986
Eben: String Quartet "Labyrinth of the World and Paradise of the Heart", Piano Trio and Piano Quintet
Harp Recital - Ravel, Debussy, Jolivet, Tournier
David Post: Concertino á cinque & Piano Quintet
Elliott Miles McKinley: Infinite Landscapes
Mozart: Clarinet Quintet - Beethoven: String Quartet, "Harp"
Dvořák: String Quartets Opp. 105 and 106
Martinu: Piano Quintets Nos. 1 & 2 / Sonata for 2 Violins and Piano
Martinu, B.: String Quartets Nos. 4, 5 and 7
Martinu: String Quartets Nos. 1 and 2 / Three Horsemen
Mysliveček, Richter, Krommer-Kramář, Vranický: String Quartets
Mysliveček, Richter, Krommer, Ryba: String Quartets
Quartet No. 12 in F Major Op. 96 "American" I. Allegro Non Troppo
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 0x32c4bd64d6fc49164990e268b1acb4cb0e5dcf5812a5463790c3710eec791519. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/QMQL91200034.
Quartet No. 12 in F Major Op. 96 "American" II. Lento
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0f6d361f1514447cb52f820c1d27c3a1f1440bf3215dd0a48b7b25b0f48340e8. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/QMQL91200035.
Quartet No. 12 in F Major Op. 96 "American" III. Molto Vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6967b2aa5c70238e01b0a46a24cfabf3325bdd96282a89b0014c98581cb4b64f. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/QMQL91200036.
Quartet No. 12 in F Major Op. 96 "American" IV.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa8fabcbeb8e8b06aa2a69c497688d014da5da30e236d367f6f967118e476ae8d. Chain 2 (Bitcoin): anchored in block 960481 (2026-07-31T23:51:35Z), 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/QMQL91200037.
Quartet No. 14 in A Flat Major Op. 105 II. Molto Vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x62aabeccf5802bde7a4ba7a6c04c508460638300b49c91711ea20045543811d0. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/QMQL91200039.
Quartet No. 14 in A Flat Major Op. 105 III. Lento Cantabile
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x23aa8c2640054e5492fd969fd48c37c6c409fb9ca779fccb624b3a0bafd66e1f. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/QMQL91200040.
Řezáč: Squaring The Heart - Teml: Fantasy for Violin, Harp and Orchestra
Bartoň, Graham, Havelka, Kopelent, Matějů, Pokorný: Czech Contemporary Clarinet Music
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4cd9b062fe29e15be329c7df2233b43b95943880636397f6b7f491ac82404693. 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/CZA169500409.
Francaix, Bordes, d'Indy, Pierne & Jolivet