Guy Jeffrey Barker, (born 26 December 1957) is an English jazz trumpeter and composer. Early life Barker was born in Chiswick, London, the son of an actress and a stuntman. He started playing the tr
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 0x56611834ac9473ce4bc15eac1ecaf27bfdba41cefdd51e8bab8d509589ece072. Chain 2 (Bitcoin): anchored in block 953408 (2026-06-12T19:28:13Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/78ec3040-3ef7-4480-9b55-624af462510a.json and https://artists.proofprofile.net/proofs/artist/78ec3040-3ef7-4480-9b55-624af462510a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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 0x3191305524b4fb266a59e3bc07d6a290b420ef2efd7e0db9d2ce9445eb23f371. Chain 2 (Bitcoin): anchored in block 956351 (2026-07-02T11:38:34Z), 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/GBLNL0100003.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xde51b514234ff50fe54173023e4d007dfdf2462323107d4d2cd2ce4d934d7fad. Chain 2 (Bitcoin): anchored in block 957075 (2026-07-07T18:50:38Z), 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/GBLNL0100004.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5650526f7c52b73ce342fb853ed5ac09d2d62840d469ce2e0b646e5e9d5ff805. 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/GBLNL0100005.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfd423459c6d22eccb037c8e911be2f107b838057ba1090ba7789addbc1fe9bee. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/GBLNL0100006.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x51d82f137cae5ac9937ab00f4e31e9b7f619c46ac8091214aa1e4fafa25e39d9. 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/GBLNL0100008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x15fe7529b7212ef9c0921908f2d8c1efbed50e2dd165314336ea7c02a8051671. 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/GBLNL0100010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa6081e8b74c4a08389e65dbab7ef7cbebab4459f2881dab3f769b4435cc8ab31. Chain 2 (Bitcoin): anchored in block 957012 (2026-07-07T08:27:05Z), 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/GBLNL0100011.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6cb2927eedd5b98bcf4185724e11c3d258f02ee553df7a8c93ae11abf2c081b6. Chain 2 (Bitcoin): anchored in block 960207 (2026-07-30T04:47:22Z), 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/GBLNL0100001.
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 0xcb27cf756cd04b7bb5a2fd45645930c69ab52bb8fc3a3d32abbb381c55c6d6a4. Chain 2 (Bitcoin): anchored in block 960222 (2026-07-30T07:48:45Z), 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/GBLNL0100002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3c3da3e8112169fff783e5eb1d2de73ff8ddabbb61fd68ad8975f1be0b11c3cb. Chain 2 (Bitcoin): anchored in block 960254 (2026-07-30T12:06:10Z), 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/GBLNL0100007.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7f09fab814806f715697b44e92642941d7ffc7276bdc9e34b04b35be3024ddc8. Chain 2 (Bitcoin): anchored in block 960250 (2026-07-30T11:13:28Z), 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/GBLNL0100009.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x16f5a762838e12ea1125526dea671be9fe0cb0affc6f9f6d4910d1883fac850f. 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/GBLNL0100013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x10bd723ae213be6453e2395b7b60ed521435d01c61aad35fe40e4e0d022eb386. 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/GBLNL0100014.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x296701a1b5a7ad0981b1b016fa8aacd47f17bc9994ad9e8dabbbe576a92eb518. Chain 2 (Bitcoin): anchored in block 960284 (2026-07-30T17:23:26Z), 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/GBLNL0100015.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe7deb9b9f084d8e50da992cc116c7866fe19ba5c656962233554326c2f69dca3. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBCWU0601059.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7d8d3d055b04f9a7e7a7c2d56c4db3a82870c0ccedaab80a23bc8ad485844d7a. 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/GBCWU0601061.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd037ebba095d7441c0b9bc4168c189d55e3c31541ae8410237ffd5b90594a260. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/GBCWU0601066.
Piazzolla: Oblivion (Arr. Barker & Balsom for Trumpet and Orchestra)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x23d7011c1d7cc442589cfd6048b97ad8639a908498be2776e951c3e131bcdeeb. Chain 2 (Bitcoin): anchored in block 957061 (2026-07-07T16:07:00Z), 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/GBAYC1402142.
Satie: 3 Gymnopédies: No. 3, Lent et grave (Arr. Barker & Balsom for Trumpet and Orchestra)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1c8e5b45d4c0113c8f91134081db6668af826550651dec82eb859b68c3c6f8a1. Chain 2 (Bitcoin): anchored in block 957055 (2026-07-07T15:12:44Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBAYC1402149.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4f9dfa3ee2977f9a3c67ed5ed1d621390e5adcdffd84d7e5f0fc23915518a56e. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/GBAYC1402150.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1c8e5b45d4c0113c8f91134081db6668af826550651dec82eb859b68c3c6f8a1. 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/GBAYC1402149.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x23d7011c1d7cc442589cfd6048b97ad8639a908498be2776e951c3e131bcdeeb. Chain 2 (Bitcoin): anchored in block 953520 (2026-06-13T13:32:09Z), 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/GBAYC1402142.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3e61c32d828e3488e869f3384df7ec28032cf4ddec7d84365d0ce1cbde926f90. 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/GBAYC1402143.
Ravel: Vocalise-étude en forme de habanera, M. 51 (Arr. for Trumpet and Orchestra)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe4462f5c81f3471c6743682bbede175abe6a3e946d095ba9bb516977cef6d620. Chain 2 (Bitcoin): anchored in block 956351 (2026-07-16T13:51:10Z), 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/GBAYC1402147.
Satie / Arr. Barker & Balsom for Trumpet and Jazz Orchestra: 6 Gnossiennes: No. 3, Lent
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf85040e89801067febc31021a12dd5445923dad1a6fd2488428efa4e508e5f0b. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/GBAYC1402140.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4f9dfa3ee2977f9a3c67ed5ed1d621390e5adcdffd84d7e5f0fc23915518a56e. 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/GBAYC1402150.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0717eeed80835b4895b4700b0ae380772082bb976639bc301374964eeb168b02. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), 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/GBAYC1402151.
Satie / Arr. Barker & Balsom: 3 Gymnopédies: No. 3, Lent et grave
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1c8e5b45d4c0113c8f91134081db6668af826550651dec82eb859b68c3c6f8a1. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), 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/GBAYC1402149.
3 Gymnopédies: No. 3 in A Minor. Lent et grave
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1c8e5b45d4c0113c8f91134081db6668af826550651dec82eb859b68c3c6f8a1. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/GBAYC1402149.