The Latvian Radio Choir (Latvijas Radio koris) is the professional chamber choir of Latvian Radio which was founded in 1940 by the Latvian conductor Teodors Kalnins. Following the musical direction by
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 0x5b43f95c7d0113388c8a7444d3077916ab639487d28e2e75ea48f82ce85c5016. 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/86bd5274-aff4-483a-9ac3-f058e3988b29.json and https://artists.proofprofile.net/proofs/artist/86bd5274-aff4-483a-9ac3-f058e3988b29.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
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 0x45aacbfdc7fbc8a1d6a6e1075ad2b1c75d209391e3d3435750ec544404a241a4. Chain 2 (Bitcoin): anchored in block 960473 (2026-07-31T22:27:44Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ130311010 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x20b409341c7eba2e48a5d41f4127968f1e1f06bf8cfa368e426d71df57b9513b. Chain 2 (Bitcoin): anchored in block 960321 (2026-07-30T22:27:30Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ130911030 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3669922d8274c2e0d1185d90ec62aed04d9e7e031996d769dd86311da6b7e8b2. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300134 — a six-check JSON result.
Symphony No. 7 "Seven Gates of Jerusalem": III. De profundis
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe1a043a1398d90f0d3ebcc982f6f9ab1ece50fb42df12a242bfbc9496e0727b0. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300135 — a six-check JSON result.
St. Luke Passion, Pt. 2: No. 20, In pulverem mortis
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9a8017ea0bd84c46e89e2c6439ded2fb67bc9bd96d4ed41aef50da4815e450bc. Chain 2 (Bitcoin): anchored in block 960273 (2026-07-30T15:42:38Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300136 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x02040bf2e50b93b053db8a9b04304e9307bef2b05654069171c61ed40d3f6274. Chain 2 (Bitcoin): anchored in block 960229 (2026-07-30T08:30:10Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300137 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x81debeb0afd0cf00a8b753e8c99422968d2db991d9ae8945745568b3a9826235. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300138 — a six-check JSON result.
St. Luke Passion, Pt. 1: No. 12, Miserere mei, Deus
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x68357410524da374100ea2ac1d9c1711b139aa80482730062a28063a9659974a. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300139 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x30badaebb0dd41283d7dd525893bb9d5b76076496a4110894e7bfe71f4b8505e. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300140 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b229d6987d25731b1dc56915802be58e1125e490d9cbc3e9231d42e0d8462f3. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300141 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x151703b066bff93a0ba4d29f652d0035a10c3c05658f2d2782b32e9a7cee7067. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300142 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1d03283c72c7199d7a519d58b095e3803f49ab4e865e39ebee19b0fc0deca007. Chain 2 (Bitcoin): anchored in block 960381 (2026-07-31T09:50:11Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300143 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x00c6b4f7b2fb45aec2878452149bddb6a665db772f4558b0c75b62488a6a91b6. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300144 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4beeec0c89d8d65e0ef86b849ddad45e6d2968ef90fc08e6b3a1732ee546aa8f. Chain 2 (Bitcoin): anchored in block 960427 (2026-07-31T15:59:18Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300145 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x112122a72aa51bb07bc362416e0210df3f550c81bed7856ad34d4bf03dad0068. Chain 2 (Bitcoin): anchored in block 957122 (2026-07-08T03:39:04Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE2300146 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4f4ee51dbae09ba4d65cb5fb61b879b5af0de726401595c4e32fc4d98e65b9c9. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152202068 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd9b372c5e1c6bb980f3f71f82b3230961e388e156ea5face850a9e06c0154b53. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152202083 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdc5b7343b42fca68a8561323bdb8eda3822254386e5a5cfda4cda00b5042f227. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152103028 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a58f204d84498961cb91e62e9ac58147f5dc6d8b262f4bdc614c05566efe5e6. Chain 2 (Bitcoin): anchored in block 960266 (2026-07-30T14:44:50Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152103017 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7dd773fa01c2faa5400315d8c59e97b57cf1433b260df08324832d30d06a573f. Chain 2 (Bitcoin): anchored in block 960455 (2026-07-31T19:53:13Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152103012 — a six-check JSON result.
Tchaikovsky: All-Night Vigil & Other Sacred Choral Works
Zālīts: Complete Choral Songs (1884-1943)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2250c2fc522bf563226346df573a72ccf3e40a8e6b5f72998c4fcf0a21c6b2c0. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FINDE1700154 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x3740ebd37620b2d3edce7a928eb79b8e7eaef150e0d55dc91bea1349689fdacf. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152400405 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe5faad67a9af47285eaf78b3ce304f6b6ad1a660fe4506ca3318991fb1f84bcf. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152400404 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd270bc330a3b932fe72158f9f89812cb1d3c680c61fd47211195720a43340669. Chain 2 (Bitcoin): anchored in block 960273 (2026-07-30T15:42:38Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152400722 — a six-check JSON result.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x016167171767bbdd39562d9f26c4fc3ebebdd1ef7742286247a342104c48d553. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/LVL152400400 — a six-check JSON result.