Horacio Arturo Ferrer Ezcurra (2 June 1933 – 21 December 2014) was a Uruguayan–Argentine poet, broadcaster, reciter and tango lyricist. He is particularly well known for having composed the lyrics f
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 0x259b8d81b203170a86d10334a24c75e4cec5e1b9c5c1fa1abc23d3deada4ee47. Chain 2 (Bitcoin): anchored in block 953778 (2026-06-15T11:57:35Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/cd97644a-5224-49f9-a9d9-58743e11247e.json and https://artists.proofprofile.net/proofs/artist/cd97644a-5224-49f9-a9d9-58743e11247e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Moriré en Buenos Aires (Vida y Obra de Horacio Ferrer)
El pueblo joven (Oratoria de dos mundos)
Flor de Tangos y Poemas (feat. Juan Trepiana)
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 0x9b520afa23e0217a2bf1ea13d31a95f4c8c54e32211ea1c51c5a5bdc80dc6e45. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), 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/AR2P01400007.
Tango en Granada. Festival Internacional de Tango, 1993
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a385864dfd01c529d31b94debbab2a8ff6e2be8424e290266a190c041cfbe78. 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/ES7739306035.
Tales and Myths of Gothia - New Music for Concert Band - Demo Tracks 2018-2019
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a094ac84ea3053e0f47207f7bf210c66988f69b98245546f854da152862cff7. Chain 2 (Bitcoin): anchored in block 960218 (2026-07-30T06:57:05Z), 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/NODGN1807030.
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 0xddfb587f4ecb7ed75e3f561824fa140ca3be1b496903d4761b9dfef9ebe65309. 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/ARR9V2200011.
Piazzolla / Arr. Desyatnikov: María de Buenos Aires, Scene 1: Alevare (El duende)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1e2edde218fa3b102d5d0601f1a2a29ec502aae1aeccec35daaeef716da12a66. 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/DEA809800100.
Piazzolla Íntimo en el 16. Rue Descartes (Tango en París)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd3b74507843e3b64946a8bc59dbfb7b382a84639346783685477a77cf4e6a015. Chain 2 (Bitcoin): anchored in block 960478 (2026-07-31T23:30:38Z), 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/ARU8P2100003.