thumb|right|Lutenist Rafaelle Calace holding a liuto canabile. This photo was taken by 1901 and was featured in Samuel Adelstein's book Mandolin Memories, printed that year. Raffaele Calace (1863 – 1
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 0x9b763d6ecda863649a0f320d2a7549c701a38621721e1eaa51a994a0b15f0a1d. Chain 2 (Bitcoin): anchored in block 953654 (2026-06-14T16:26:51Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/48a3fc64-d0d9-4080-9901-db7c4cb5969e.json and https://artists.proofprofile.net/proofs/artist/48a3fc64-d0d9-4080-9901-db7c4cb5969e.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Concerto for Mandolin No. 2 in A Minor, Op. 144: I. Maestoso
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 0x94b044704216b7d014a06bf70def5dfae49d4446eabefb9cdf1fb26f50e0834f. Chain 2 (Bitcoin): anchored in block 956349 (2026-07-02T11:34:59Z), 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/FRZ131810040.
Mandolin Concerto in C Major, RV 425: III. —
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3096e76e96c321dd73c7720e9445b7fe68512e35d065a281b5e50d81930a0659. 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/FRZ131810090.
Concerto for Mandolin No. 2 in A Minor, Op. 144: II. Largo mesto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf1b974f3b438b1c389ead36841b4c17330569dabdb24691f433c328ea9c8c1cc. Chain 2 (Bitcoin): anchored in block 960327 (2026-07-31T00:26:26Z), 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/FRZ131810050.
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
Concerto for Mandolin No. 2 in A Minor, Op. 144: III. Allegro non troppo
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x312d3458f6cc32ff74c50fca11f1d0bc2b27137e563ade9c6a9cf68054df1f4b. Chain 2 (Bitcoin): anchored in block 960230 (2026-07-30T08:32:18Z), 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/FRZ131810060.
Delicate Delights: Best Loved Classical Mandolin & Lute Music
Calace: Mandolin Concertos Nos. 1 and 2 / Rhapsodia Napoletana
Raffaele Calace: Duets for Mandolin and Guitar
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x86e608b1198588331964c0224b2dd78a75c83c2cd5054dfdfe4ba0fcfb90c72a. 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/USCGH2273586.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xddb383415dd480ca6daf558212b12d3c035ad61a5e100c364a5649b6608a96f1. 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/USCGH2273596.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xba17e9b5cf2514eb14e9ce7650a35f7107fd26018470f0502472d90b01a87a38. 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/USCGH2273602.
Raffaele Calace: 10 Preludes For Solo Mandolin
Calace: Complete Works for Mandolin & Guitar
Raffaele Calace: Le Opere Per Quartetto E Orchestra A Plettro
Notturno Cielo Stellato for Solo Mandolin, Op. 186
Raffaele Calace: Barcarola per liuto cantabile, Op. 116
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xda9b54e7362c808e60e185c5eb689ed0c6b5309dbe67fdcbe372e0f548a3a201. Chain 2 (Bitcoin): anchored in block 957073 (2026-07-07T18:39:05Z), 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/QZSR42101660.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3895098bafbbdea93eee89f554c7d5b1b87e427905e481a4d99a7be4fe27dbc8. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), 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/FRZ131601070.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc90f5f9325734e11caba0a77a31708ffcf2fb1fb6e95084e479f97cdfffe1c8b. 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/FRZ131601080.
BMO 002 Brasschaats Mandoline Orkest olv Marcel De Cauwer
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3c81315a2998d50cf47ae6f38dafb4d1e38e89c0c79940f79e9cc4889fe2fc20. 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/ATR981168735.
Munier & Calace: Works for Two Mandolins, Mandola and Guitar
20th Century Italian Chamber Music with Mandolin