Boris Christoff (, ; 18 May 1914 – 28 June 1993) was a Bulgarian opera singer, widely considered one of the greatest basses of the 20th century. Early life thumb|left|Boris Christoff (photo with 19
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 0x9a7d7f77609a00b3c5be5375dd28b8abd4754e776d8a4ce14a2e0fb2439a8767. Chain 2 (Bitcoin): anchored in block 953772 (2026-06-15T10:33:29Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/c82f1ad3-125c-4f83-93de-fbddd960ef5a.json and https://artists.proofprofile.net/proofs/artist/c82f1ad3-125c-4f83-93de-fbddd960ef5a.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Orchestre du Théâtre National de l'Opéra de Paris
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 0xa35898aaee0aad779f247aaf50ebf6b7d6a492c985144a017e3a40069b40de2e. 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/FRZ115307117.
Mussorgsky: Boris Godunov, Prologue: Introduction
Orchestre National Radiodiffusion Française
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Mussorgsky: Boris Godunov, Prologue: "Nu, chtozh vy?" (Officier, Chorus)
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Mussorgsky: Boris Godunov, Prologue: Shchelkalov's Adress. "Pravoslavnye! Ne umolim boyarin" (Shchelkalov)
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Mussorgsky: Boris Godunov, Prologue: Pilgrim's Chorus. "Slava tebe, tvortsu vsevyshnemu" (Chorus)
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Mussorgsky: Boris Godunov, Prologue, Coronation Scene: Introduction
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Mussorgsky: Boris Godunov, Prologue, Coronation Scene: "Da zdrastvuet tsar' Boris Fedorovich!" (Shuysky, Chorus)
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Mussorgsky: Boris Godunov, Prologue, Coronation Scene: "Slava! Slava! Slava!" (Chorus)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8125a8ce87251eb834d4883e09c2bd487771ff16f0c70e6eef37e9f3e3485baf. Chain 2 (Bitcoin): anchored in block 960379 (2026-07-31T09:25:34Z), 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/FRZ115206634.
Mussorgsky: Boris Godunov, Act 1: Pimen's Monologue. "Eshche odno poslednee skazan's" (Pimen)
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Mussorgsky: Boris Godunov, Act 1: Grigoriy's Dream. "Bozhe krepkiy pravyi" (Chorus, Grigoriy, Pimen)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcea2a37e9999b8089dbb7f5efe440b8f0f4edfc68f0dcb102f01067c7eea23b3. 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/FRZ115206636.
Mussorgsky: Boris Godunov, Act 1: Grigoriy's Dream. "Ty vse pisal i snom ne pozabylsa" (Grigoriy, Pimen)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8e10e129de7eff851388bf762fc2607ddc189ca1bec23fbc602018e3e2f17a4d. 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/FRZ115206637.
Mussorgsky: Boris Godunov, Act 1: Boris' Crime. "Davno, chestnoy otets" (Grigoriy, Pimen)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb6924c75feedde9dd322fd2cab43793ec7bb3fec78a7e7db22764fe85d83bc47. Chain 2 (Bitcoin): anchored in block 960481 (2026-07-31T23:51:35Z), 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/FRZ115206638.
Mussorgsky: Boris Godunov, Act 1: "Zvonyat k zautreni" (Chorus, Grigoriy, Pimen)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf77bf5fd13aec58fcdc02ee99c1d79898bff49f2b0ee3f3c96fa050369339d32. 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/FRZ115206639.
Mussorgsky: Boris Godunov, Act 1: Song of the Hostess. "Poymala ya siza seleznya" (The Hostess, Varlaam, Misail)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5da36e44ccc88221ea8aac284971d1634a708d82f0bb7668f5ceb6309ee91c30. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ115206640.
Mussorgsky: Boris Godunov, Act 1: "Zheno, mir domu tvoemu!" (Varlaam, Misail, The Hostess, Grigoriy)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x20d83e2366e2d290a3f12640799fc281c1d1e105038d17f08072340e4a198e60. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ115206641.
Mussorgsky: Boris Godunov, Act 1: Drinking Song. "Kak vo gorode bylo vo Kazani" (Varlaam, Grigoriy, Misail)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x528c65ca794db3b7e1ffaea197f6b4ab806a7d33adc6010eedec9e96abfffd9a. Chain 2 (Bitcoin): anchored in block 960352 (2026-07-31T05:48:30Z), 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FRZ115206642.
Mussorgsky: Boris Godunov, Act 1: "Kak edet en" (Varlaam, Grigoriy, The Hostess)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7556565ae697cb2fc64fd261393443a6ae1fc6542d6b1cef5f3cc06c654cd181. 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/FRZ115206643.
Mussorgsky: Boris Godunov, Act 2: Clock Scene. "Uf, tyazhelo!" (Boris)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x6df8164bea89b0081a32b65af427d92fe0d49731afe184f4111e75b91369a516. 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/FRZ115206657.
Mussorgsky: Boris Godunov, Act 4: Council of Boyars. "Chto zh, poydem na golosa, boyare" (Chorus)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa6926e0018cbf0651ab9a0315f5f7f3d3af4b0aaba7aa48e92fd424c261ebe8f. 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/FRZ115206675.
Tchaikovsky: Mazeppa (Sung in Italian) [Recorded Live 1954]
Don Carlo, Act II: È lui! Desso… L'infante!
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4b1055befafbf7072f8ff44a632ec1030b706219ab325ed988d38081760d0d0. Chain 2 (Bitcoin): anchored in block 960163 (2026-07-29T23:20:38Z), 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/ITCC51100328.
Die Meistersinger von Nürnberg sung in Italian
Les plus belles musiques du monde : Splendeurs du chant russe, Vol. 1
Wagner: Die Meistersinger von Nurnberg, WWV 96 (Sung in Italian)
Mussorgsky: Khovanshchina (Sung in Italian) (Live)
Verdi: Don Carlos (Live Recordings 1958)
Glinka: A Life for the Tsar (Arr. N. Rimsky-Korsakov)
Lebendige Vergangeneit - Boris Christoff (Vol. 4)
Claudio Monteverdi, L'Incoronazione Di Poppea
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Lebendige Vergangenheit - Boris Christoff (Vol.3)
Edition Herbert von Karajan, Vol. II (Verdi: Messa di Requiem)
Boris Christoff - Arias form Russian Classical Operas
Lebendige Vergangenheit - Boris Christoff (Vol.2)
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Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x112368ae4d640c1fd79e07756e7d9b555f18bfea476870ebea4f701dc032b1d2. Chain 2 (Bitcoin): anchored in block 960459 (2026-07-31T20:22:46Z), 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/BGA260704002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9ba0e848790bd48f0d62d6ea30069c3f58fd4af9fa1bdc3b2d526e88e9775b06. 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/BGA260704003.
Hvalite Imya Gospodne (Praise the Name of God)
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Razboinika Blagorazoumnago (The Jubilicious Villain)
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Veliko Slavoslovenie (The Great Glorification)
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Mnogaya Leta (Grant, Oh Lord, Many Years)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x54feb511cdc7b24cb1e9959d836b3d0dee573b1a2fe37015eb69cc2dbebf6c39. Chain 2 (Bitcoin): anchored in block 960334 (2026-07-31T02:19:15Z), 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/BGA260704009.
Lebendige Vergangenheit - Boris Christoff
Boris Christoff - The Great Russian Bass Roles
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Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x18ffd73825a923a6edf9b7169112cea4c8b1b122cd04060595ec03e875bfef95. 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/FRZ110300011.
Verdi: Don Carlos (1886 Version, Mono Version)
Singers of the Century: Boris Christoff - Italian & Russian Opera Recital
Weber: Der Freischütz, Op. 77, J. 277 (Sung in Italian) [Live]
Boito & Bellini & Bellini: Great Voices of the Century - Baritones & Basses Vol. 3
Mussorgsky: The Nursery: No. 7, Sailor the Cat
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Faust - opera in five acts (1989 Digital Remaster), Act II: Le veau d'or est toujours debout! (Méphistophélès/Choeur)
Choeurs et Orchestre de l'Opéra National de Paris
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Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x443a3087b8a168236c347a3b00317a364be1b5e8e27cca40b40eafdb89fb5b54. 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/GBAYC1103044.