Barbara Buntrock (18 February 1982) is a German violist and music educator. Life Born in Wuppertal, Buntrock received her first violin lessons at the age of five. From 1991, she was a student of Ma
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde2957b9db4cdc7f2382962e686c263e032a3d516e632edb026aef54aa705b3e. Chain 2 (Bitcoin): anchored in block 954533 (2026-06-20T08:57:02Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a2d9c747-48fc-4115-ac9f-6374111f9e4f.json and https://artists.proofprofile.net/proofs/artist/a2d9c747-48fc-4115-ac9f-6374111f9e4f.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Tchaikovsky & Borodin: String Quartets No. 2
Serenade for Clarinet Quartet in B Major, Op. 4: II. Adagio ma non troppo
Serenade - Works for Clarinet and Strings by Krenek, Gál and Penderecki
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x37b454302e477863db3a8c871dbc72347d336df4326b87eab8c054ae6a960130. 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/DEAQ72453702.
Serenade for Clarinet Quartet in B Major, Op. 4: V. Allegretto grazioso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xca7ced13133ce375a62aaf7d81816cb64e8edea596b6a840439514f7414abbae. 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/DEAQ72453705.
Piano Quartet No. 3 in C Minor, Op. 60: I. Allegro ma non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0730e1adfb1da56f6fb059859a3ab8c696f17fcac9bd266250932d8d5ef9504d. 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/FINDE2400005.
Piano Quartet No. 3 in C Minor, Op. 60: II. Scherzo. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4b672f1f859eb5c97434b46ecc13f5a21521c5334747a3703c468c1a98e38692. 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/FINDE2400006.
Serenade for Clarinet Quartet in B Major, Op. 4: I. Moderato
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5b5f20afd1e2441a69d33c57b60f127acf67cac70502910eb6db7f45d9719812. Chain 2 (Bitcoin): anchored in block 960181 (2026-07-30T00:53:20Z), 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/DEAQ72453701.
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
Serenade for Clarinet Quartet in B Major, Op. 4: III. Allegro molto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeea75a8edaf7ad8529fb1e8f0d9172aef6d147c7bfd5122c413798b681c2c1a1. 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/DEAQ72453703.
Serenade for Clarinet Quartet in B Major, Op. 4: IV. Langsamer
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9fee31890b0d64d9bcfc2268c03cb283835430f9c724278e30df0dc9f43393a5. Chain 2 (Bitcoin): anchored in block 960389 (2026-07-31T10:20:10Z), 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/DEAQ72453704.
Serenade for Clarinet Quartet in B Major, Op. 4: VI. Allegro vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x68414c7197a66454670a412cd742a791e260ee768e9ac8db3d09d9d12217b3ed. 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/DEAQ72453706.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x33b68ce4d7e0a0de1bc77d40a2a1f17a0af1b93ffa361fe13c11099dbb59dfc2. 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/DEAQ72453711.
Clarinet Quartet: III. Serenade. Tempo di Valse
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x482dfa4817c5c469173931afc0eb04f9e487870ca3da1e3da74f1eb16b5515de. 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/DEAQ72453713.
Piano Quartet No. 2 in A Major, Op. 26: I. Allegro non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfc935b01966bd2a5dd4da98606594f925feb7bb3f730b2b9110b85674a961ba6. Chain 2 (Bitcoin): anchored in block 960121 (2026-07-29T15:22:21Z), 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/FINDE2400001.
Piano Quartet No. 2 in A Major, Op. 26: II. Poco Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x593bb93e10a61fb7b802ebe57d2b71095b324977709d763c4ee55e718aee7025. 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/FINDE2400002.
Piano Quartet No. 2 in A Major, Op. 26: III. Scherzo. Poco Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5c632755b246044ea4741d937fbaf336a5471c7c03ca99628828bebe546c6d31. 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/FINDE2400003.
Piano Quartet No. 2 in A Major, Op. 26: IV. Finale. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc41a870f38683810ee7da35d85e85b1226eaf9beee748645a3a1a7879d7ceca3. Chain 2 (Bitcoin): anchored in block 960220 (2026-07-30T07:28:30Z), 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/FINDE2400004.