thumb|300px|right|Mark Reizen Mark Osipovich Reizen (, – 25 November 1992) was a leading Soviet opera bass singer and pedagogue. People's Artist of the USSR (1937). Life and career Reizen was born
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 0x6812cb205e59253d0f4964a6409e82932afe5c344a97a10fd0873f0d2b963879. Chain 2 (Bitcoin): anchored in block 954784 (2026-06-22T02:53:59Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/eadf0930-c8ec-479a-aedc-dba7a7412ac7.json and https://artists.proofprofile.net/proofs/artist/eadf0930-c8ec-479a-aedc-dba7a7412ac7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Gonoud: Faust, CG 4 (Sung in Russian) [Recorded 1948]
Borodin: Prince Igor (Ivanov, Smolenskaya, Melik-Pashayev) (1951)
Soviet Film Soundtracks (1928 - 1950), Volume 3
Tankmen´s March (From "Tractor Drivers")
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 0xe209c0ba4dff9456462b1956ec177ceee058a9c6968c2ee0b1e70e55805f0c9a. 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/QM6N21438480.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x91ab41abfa8a870d8e3b56658ee015cc5c509d4dec5a6937f1913fc1455d126f. 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/QM6N21438492.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5fe832980fdf0867d966038c4fdfc8fcd95fb1d4bdefecc9ba21516ba49c2b5c. 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/QM6N21438494.
The Queen of Spades, Op. 68, Act III Scene 7: Herman`s Aria "Chto nasha zhizn? Igra!"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ec7600253138360df4ca8cacb7ece3680c377d3529039c73a4c200fbd05e1ec. 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/UK2Y21310549.
The Nutcracker, Op. 71, Act II Scene 3: Dance of Prince Orgeat and the Sugar-Plum Fairy
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6399a71ed3c5f131e1d2f3ed350cd9cad9589e91ab32c3d8101fce8d55bae7de. 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/UK2Y21310538.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdd635e5284a415d2db4d087262c995fddb0e1d2bbc3a8badf85fdbf4b007029c. 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/UK2Y21310524.
Romeo and Juliet, Op. 64, Act I Scene 2: Dance of the Knights
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x78380d187ed5ee39b5fc39295ae5cbdc03ee0ed33ef2adf876768a96d1c1a99a. 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/UK2Y21310553.
Rachmaninoff: Complete Operas, Cantatas & Fragments
Anthology of Russian Romance: Basses in the Russian Vocal Tradition Vol. 2
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xfa99ffc23abece01b0690d83def32b8906b7c68094202cbbfd045deb1b441962. 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/RUA150702244.
Dargomyzhsky: Rusalka, Op. 4 (Excerpts) & Other Vocal Works
Mark Reizen: Airs d’Opéra Russes (Russian Opera Arias) (1948-1955)
Mikhail Glinka: A Life for the Tsar "Ivan Susanin" (1950), Volume 2
Mikhail Glinka: A Life for the Tsar "Ivan Susanin" (1950), Volume 1
Rimsky-Korsakov: The Maid of Pskov (Excerpts)
Lebendige Vergangenheit - Mark Reizen (Vol.2)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x593c927c4bea8172950c9de6993edf659b7450430a950c5e3de801af0ce0035e. 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/QMFMG1442597.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a37c244472903205f04f99b554e7ee8480c29f673fb83fed1bfb5126d60f21b. 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/QMFMG1442594.
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 0xed48e6bd56771c12851afa3efb68dfd0dee5d10b86a16dfb0a5b54ff7d3084db. 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/UK2Y21308001.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2d93e7934963dd3021a5cc8f3f7b7a7fd13cd6cf521675d13ad44ac66e148174. Chain 2 (Bitcoin): anchored in block 953515 (2026-06-13T12:53:06Z), 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/UK2Y21308008.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf40a3501f700b5ca6e1e0788e53fbdc82cdb1e1eac26bc277d653dcebeafa072. 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/UK2Y21308013.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xadf86decf12458e3260026a9b74fcc1ab1bb9e32b43e13933dbe57d5de97a239. 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/UK2Y21308017.
Инструментальный квинтет п/у Виктора Миронова
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdc68c23c0a424050571cece7bb7dcaea6b8865b61dde5b6d980e4652d9a6b80e. 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/UK2Y21308018.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x272b5ff8a0fbb1541cb217141214a4181bb55c10afa587e0e4d9276a50c9e565. 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/UK2Y21312203.
Марш "Вступление Красной армии в Будапешт"
Separate Orchestra of the Ministry of Defense of USSR
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbeeaa6696a67a4ed46464ea0c835bd3184864a4879561ce9ea046b38e0ea6267. Chain 2 (Bitcoin): anchored in block 956351 (2026-07-02T11:38:34Z), 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/UK2Y21312209.
Образцовый оркестр военно-морского флота СССР
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4427015cd2e1aedf67011712114fdf606a6a0c8c3a9e05a77190cb6a63c9fe11. 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/UK2Y21312210.
Rimsky-Korsakov: Complete Operas & Fragments
Mussorgsky: Khovanshchina (Freidkov, Nechayev, Khaikin) (1946)
Voices behind the iron curtain - Soviet Singers of the Stalin Er
Glinka: Ivan Susanin (A Life for the Tsar) (Mikhailov, Spiller, Melik-Pashayev) (1947, 1950)
Legends of Bolshoi: Highlights from Russian Operas (1947-1957)
Modest Moussorgsky: Boris Godunov (1948), Volume 1