thumb|Sergio Vartolo in his studio with (June 2003) Sergio Vartolo (born in Bologna in 1944) is an Italian harpsichordist, organist, musicologist and conductor; in the past he was also active as a co
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 0x6d4c14f9b0fc65026b73b64b119254e3ef1cd39ee798f9d21c6285fd0aa18ff1. Chain 2 (Bitcoin): anchored in block 953750 (2026-06-15T06:12:23Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/aa734f1d-9bfe-402a-82f4-9a3324111450.json and https://artists.proofprofile.net/proofs/artist/aa734f1d-9bfe-402a-82f4-9a3324111450.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Monteverdi: Il ritorno d'ulisse in patria
Rinaldo, HWV 7, Act II Scene 4: Lascia ch'io pianga (Let me Lament)
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 0x93fcb40236d7a8323ae13f9beec842682d7c07eb472c52d1baef95adc9ad1aad. Chain 2 (Bitcoin): anchored in block 960241 (2026-07-30T09:58:01Z), 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/HKI190023703.
Lakmé: Blumenduett (Lara Croft Tomb Raider): Lakme, Act I: Dome epais, "Flower Duet"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe82040ec077a426481435df6c980ca915963e9d3b04c7839260775c665623a48. 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/HKI190023811.
Carmen: Carmen, Act I: L'amour est un oiseau rebelle, "Habanera"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe1d00a2fda04f2ff9e8bbf56b799264d3562a685e50b50dca8600714a12135b0. 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/HKI190023813.
Art & Music: Caravaggio - Music of His Time
Giovanni: Salmi da Vespro per il giorno di. S. Petronio
Scarlatti: Sonate per cembalo e mandolino
Torelli: The Complete Works for 1, 2, 4 Trumpets & Orchestra
Orchestra della Cappella Musicale di San Petronio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbdbd0c811db505e8599fce5fb8089a6ac2b4a4d82577352322ea824bb90739df. Chain 2 (Bitcoin): anchored in block 960441 (2026-07-31T17:29:52Z), 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/ITDQ79555231.
Trumpet Sonata à 5 in D Major, G. 6: I. Vivace
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9b90cefa7e07479d15920769aa3952ea99e012351ba41f5f0459467d9db6997c. 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/ITDQ79575523.
Palestrina: Missa Sine Nomine - Missa L'Homme Arme