David Gabriel José Ferreira (23 August 1944 — 27 May 1977) was an Angolan musician, composer and activist. He began his singing career while Angola was still under the rule of the Portuguese Empire an
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 0x424c93a3944820e90fc969b1177f2f26f95b5933a38c2708516a2c3af7d8d0d3. 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/5a2d2681-92fe-4011-b6fa-5066c5c3be5f.json and https://artists.proofprofile.net/proofs/artist/5a2d2681-92fe-4011-b6fa-5066c5c3be5f.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 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 0xb19db72005dbab1800241bfe9948584ca9c87aec75ed300739c6d4b4df3f3b29. Chain 2 (Bitcoin): anchored in block 956545 (2026-07-03T19:59:51Z), 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/ESA011642176.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb73140c4b37c4b6295248a9a179a983bcb9147aac88e81610ec3d3583e04bf66. Chain 2 (Bitcoin): anchored in block 958395 (2026-07-17T10:10:33Z), 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/ESA011840401.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x223a8f92804ba64fcc29562e9f1da6b3c60f698f87d3901c022e28a3ec710eb5. Chain 2 (Bitcoin): anchored in block 956639 (2026-07-04T11:19:20Z), 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/ESA011840402.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x706b06ebdff77904fdf54ae16401eafa4f0cb55e38504ebebfb3f20b9703692a. Chain 2 (Bitcoin): anchored in block 958197 (2026-07-15T20:40:29Z), 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/ESA011840403.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb7976fc77bdbc7f10ada1d8aa5f3de3cad0d13498b7aa83d995f2d8f47332fb3. Chain 2 (Bitcoin): anchored in block 958690 (2026-07-19T07:14:39Z), 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/ESA011840405.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfbe4e44ba2c00fb66d18c91b5348072bf8dcf18380c334fa750b916fed3786be. Chain 2 (Bitcoin): anchored in block 958245 (2026-07-16T05:50:22Z), 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/ESA011840407.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd3b623dc2035db88bb87ff153f02207b333e05595e2e0e5efc2c8fb69f404bd3. Chain 2 (Bitcoin): anchored in block 957583 (2026-07-11T15:53:17Z), 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/ESA011840408.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x269c34ef42650283b3b3400cacd9b624792e5943608ebbc55d96f33d6a9ea244. Chain 2 (Bitcoin): anchored in block 956856 (2026-07-06T01:25:57Z), 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/ESA011840409.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x669144d3bb69ba9cd9a9edec17aa8502e134f5d8421593b3c0ade194505ab0a8. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/ESA011840410.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb9839ffad10020c4c46a1de2c3adebc0513090203dc4d25b925a0f89c9697c49. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/QM6P41585596.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x257f14f5c85b9f2276e3e55c3ac42e765ec97dcc3f3db0a333baf60a314fcfa2. Chain 2 (Bitcoin): anchored in block 958761 (2026-07-19T17:49:48Z), 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/QM6P41585598.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd9a547daba9045687f59893f459c043f555d27b60831bd2d7d18ea071f092b87. Chain 2 (Bitcoin): anchored in block 958544 (2026-07-18T12:14:37Z), 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/QM6P41585599.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe47fece37c576155f93283e8a63dde16de9d1d971899d9559006e5e4f67bf9bd. Chain 2 (Bitcoin): anchored in block 957583 (2026-07-11T15:53:17Z), 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/QM6P41585601.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcacb84552595abbc42e59d4e1f4f75809d739b55f4ef96bdc77fc4e6e13ddc7c. Chain 2 (Bitcoin): anchored in block 958157 (2026-07-15T13:14:32Z), 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/QM6P41585603.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x42cc09d78d85b57e1ac91bb1728ca170e24932fe732455d940f54204fa4c7201. Chain 2 (Bitcoin): anchored in block 956742 (2026-07-05T05:07:15Z), 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/GX3Q92333714.
Soul of Angola: Anthologie De La Musique Angolaise 1965 - 1975
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdd5d3c0bb83273721e01772805fd7af8e7c09cb7dda3d9f9e31a175b55261318. 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/FRX620153130.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x27ff70e77bf08e714d10fba227405d8a7cae88edb11eceed872c52c19e828075. 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/USV351412830.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x26e6e66adeae5761e4da0269ae116e9dd4bc6e4ac5999f9f0008d3439ea134b0. 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/USV351412832.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe6ed4a1ab0f5dd4c4315d69a7357a9cda5a632fb73ff4f5f366f64afeaa79f22. 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/USV351412834.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x25487d8326a5d56599bca8ecb7814e10ef9ee6613f97d159e5613985f7dbed10. 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/USV351412837.
Angola Soundtrack: The Unique Sound of Luanda: 1968-1976 (Analog Africa No. 9)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7cfbfc078d65b495809091b3be7c0c7954181de5f8b65cd606b5f73431084d12. Chain 2 (Bitcoin): anchored in block 960212 (2026-07-30T05:43:45Z), 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/DENR91069010.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6a3d569b4c4c48737acb44894f27a110f4619a100593f73fe160c1b2949afe6d. 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/QMFME1583540.