The Orlando Quartet was a classical music string quartet based in Amsterdam, formed in 1976 and active until 1997. Members First violin: Istvan Parkanyi, of Hungary, (born in Leipzig, Germany), (19
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 0x2c64c4ac14a6b7900b7abd43eae09848bed7a3cd3a086d377626bf614d9f8f6d. Chain 2 (Bitcoin): anchored in block 953827 (2026-06-15T19:59:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f077aa40-ebd6-4ffe-bcb7-2a04b280634b.json and https://artists.proofprofile.net/proofs/artist/f077aa40-ebd6-4ffe-bcb7-2a04b280634b.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Haydn: String Quartets, Op. 64 No. 4, 5 & 6
Shostakovich: String Quartets No. 3, Op. 73 and No. 6, Op. 101
Mozart: Complete String Quintets, Vol. 3
String Quintet No. 1 in B-Flat Major, K. 174: 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 0xe72860f6e0bb76cb1a3e4471ce6f8303efe72a1bd1f1247893e2ca43399b2296. 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/SEAEE9033010.
String Quintet No. 1 in B-Flat Major, K. 174: II. Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9347cb68775c6586995424393bb4f4451cd7aa2ee46334eb23fbe10772982873. Chain 2 (Bitcoin): anchored in block 960163 (2026-07-29T23:20:38Z), 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/SEAEE9033020.
String Quintet No. 1 in B-Flat Major, K. 174: III. Menuetto ma allegretto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x582f14f4bd39c08c2b7a421f1001240a941b677a7470c6b1c76f4e99a6a6d1fe. 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/SEAEE9033030.
String Quintet No. 1 in B-Flat Major, K. 174: IV. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x501cd97b8de31140b2c04746267610527bfb7a15dcfd7a895f92b4fe75869470. 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/SEAEE9033040.
String Quintet No. 2 in C Minor, K. 406: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7c9e96d42f6d1afb0d04a2ea2ce5df50bfd879b6ab0e765fc05b0c350356a5fe. 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/SEAEE9033050.
String Quintet No. 2 in C Minor, K. 406: II. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1663390a4a6520523ab5bb72bb020295342c07002df54487afd9022cd06497b0. Chain 2 (Bitcoin): anchored in block 960291 (2026-07-30T18:23:33Z), 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/SEAEE9033060.
String Quintet No. 2 in C Minor, K. 406: III. Minuetto in canone - Trio al rovescio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4282180b8a3aa35ecb23df8fe55121d0534d5bac1f3e4a6ed0710c8dc74fb4bd. Chain 2 (Bitcoin): anchored in block 960264 (2026-07-30T14:36:16Z), 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/SEAEE9033070.
String Quintet No. 2 in C Minor, K. 406: IV. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6329d599bf10144c52cd9003a4e7d8592335b63f8f5b4b7c16e77dfb9fd713eb. 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/SEAEE9033080.
Mozart: Complete String Quintets, Vol. 2
String Quintet No. 4 in G Minor, K. 516: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf637369a624b03651a401433d92d26363c4657751d60f1b69935195e79e83916. 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/SEAEE8932010.
String Quintet No. 4 in G Minor, K. 516: II. Menuetto. Allegretto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xca9927b18487ee5bfd1392f621988059370ad31c8dc74a10e821ecb8ef77d0bd. Chain 2 (Bitcoin): anchored in block 960309 (2026-07-30T20:35:49Z), 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/SEAEE8932020.
String Quintet No. 4 in G Minor, K. 516: III. Adagio ma non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x989023f185aa144ee86d036f0e8bc6a309f554085251d8d741277965cf675da5. 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/SEAEE8932030.
String Quintet No. 4 in G Minor, K. 516: IV. Adagio -
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb9285cbe9b6011b043df5ef51d394b8bcee730b0e7a5f1bae18338cbd601f116. Chain 2 (Bitcoin): anchored in block 960193 (2026-07-30T02:05:19Z), 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/SEAEE8932040.
String Quintet No. 4 in G Minor, K. 516: IVa. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x875fd79d683d0e4f9595c75931d082f85ee2abb2c61bdaaf673143539dfc6457. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/SEAEE8932050.
Mozart: Complete String Quintets, Vol. 1
String Quintet No. 3 in C Major, K. 515: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x759ef8e9ddc281033ca97576c10189a8999f503dd0ce98835e6f4eaae79aae4e. 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/SEAEE8931010.
String Quintet No. 3 in C Major, K. 515: III. Menuetto. Allegretto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3b9c95378449b69eafbdf4510125cd6a24b39a60460f9d60e14f82db81d07ffb. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/SEAEE8931030.
String Quintet No. 5 in D Major, K. 593: I. Larghetto - Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x838153c82cabf23df2deaffba3e1d9e0620b979f97f46170b36face1e67f4df4. 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/SEAEE8931050.
Mozart: Oboe Quartet; Divertimento No. 11; Adagio In C; Nannerl-Septett
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x296a2db95889d57218a48abf7c4c685030708472041a47b910f4a9c259bb9323. Chain 2 (Bitcoin): anchored in block 959163 (2026-07-22T18:47:29Z), 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/NLA508332301.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5359a68523559d1d375aa0e7f96f0cfaeee1a382ceacdc16bd99a373e6b40293. 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/NLA508332302.
Oboe Quartet in F, K.370: 3. Rondeau (Allegro)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4e29b7fed14ea74c581d23140bda2302895f08dd4e73ad9d711d968e54c9ca86. 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/NLA508332303.
Divertimento No. 11 in D, K.251 "Nannerl-Septett": 1. Allegro molto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcba6b89690da451f0af9bd064f8af448fbc302865db00d0eef5367768fa408d9. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/NLA508332306.
Divertimento No. 11 in D, K.251 "Nannerl-Septett": 4a. Menuetto (Tema con variazioni): Tema
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2c3e31cbd21f2992792943db129887e202c29907db5390be3405cad622bbafb9. 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/NLA508332309.
Schubert: String Quartet No. 14 "Death and the Maiden"
Haydn: String Quartets, Op. 76 Nos. 4 & 6
Dvorák: String Quartet No. 12 "American" / Mendelssohn: String Quartet No. 1
Mendelssohn: String Quartet No. 1 in E-Flat Major, Op. 12, MWV R25