thumb|Irmgard Seefried (1962) Irmgard Seefried (9 October 191924 November 1988) was a distinguished German soprano who sang opera, sacred music, and lieder. Maria Theresia Irmgard Seefried 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 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 0xa41b2837a3a8a2ca1af9f60ae48431e83a7aaf8ae084e4020988294d7aed4b27. Chain 2 (Bitcoin): anchored in block 953754 (2026-06-15T06:45:19Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/aeed5c06-6936-4cac-8f02-d39f5e5b4a80.json and https://artists.proofprofile.net/proofs/artist/aeed5c06-6936-4cac-8f02-d39f5e5b4a80.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Mozart: Une petite musique de nuit, Serenades & Nocturnes (Les indispensables de Diapason)
Mozart: Le nozze di Figaro, K. 492 (Sung in German) [Remastered 2022] [Live]
Gounod: Messe solennelle de Sainte Cécile; An Interview with Igor Markevitch (Igor Markevitch – The Deutsche Grammophon Legacy: Volume 19)
Wolf: Italienisches Liederbuch, Morike-Lieder & Spanisches Liederbuch
R. Schumann: Frauenliebe und -leben, Op. 42 & Ausgewählte Lieder (Live)
Mozart: Così fan tutte, K. 588 (Live 1954)
Mozart, Beethoven, Schumann & Others: Goethe Lieder (Live)
Mozart: Le nozze di Figaro (Live in the Royal Festival Hall, 1954)
Le nozze di Figaro, K. 492, Act I: Overture - Live in the Royal Festival Hall, 1954
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 0x31ac40944bfce06b46ef646895244d00f868f2268cce701749980c40f335ae32. 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/GBG9M1501901.
Le nozze di Figaro, K. 492, Act IV Scene 13: Tutto è tranquillo e placido - Scene 14 Pace, pace, mio dolce tesoro! (Figaro, Susanna, Il Conte) - Live in the Royal Festival Hall, 1954
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9bb87ea1e25a6b146aecb599f4b9d5cc881562a20b7d603bacf1ca7ec22fc07a. 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/GBG9M1501859.
Wolfgang Amadeus Mozart: Ein Freimaurer Bruder [Last Masonic Works]
Smetana: Prodana nevesta (Sung in German) [Live]
Irmgard Seefried (Recorded in 1944-1967)
Brahms, Cornelius, Kienzl, Marx, Mozart, Schubert, Strauss & Wolf: Lieder
Brahms: Ein deutsches Requiem, Op. 45 (Recording Live Edinburgh Festival 1953)
Wagner: Die Meistersinger von Nürnberg (Live)
Lucerne Festival Historic Performances: Rafael Kubelik (Béla Bartók: Herzog Blaubarts Burg, Sz. 48)
MASTERPIECES presents Wolfgang Amadeus Mozart: Die Zauberflöte
Wolfgang Amadeus Mozart: Messa di Requiem (Remastered Version)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcd820b325ce8fa6657c1bf7269da119984f30d729f2ce75fc2da8565f030df3e. Chain 2 (Bitcoin): anchored in block 960435 (2026-07-31T16:33:26Z), 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/FR6V80281540.
Legenden des Gesanges, Vol. 12: Irmgard Seefried (1943-1954)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x73c7eea402282ea41e6a010bad2ff2d0403a469e278e61abceb1dcfdebf8dcda. 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/DEF055702480.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x54273fb0773f6bce06dbad2767fe2158749a84fab705d32e3d274d48b6d73660. 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/DEF055702540.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0af542be71c7a65c335a875dd6905aaad3246292f4e1e4e023e5c25a588d8f3c. 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/DEF055802680.
Johann Sebastian Bach : Matthäus-Passion BWV 244
Brahms: Ein deutsches Requiem, Op. 45 (Remastered)
Matthäus-Passion, BWV 244, Pt. 1: No. 8, Aria. Blute nur, du liebes Herz (Soprano)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5cd3de0579ba408db029906927db8135be773cd2a48ec932f91e2403ff67cd22. Chain 2 (Bitcoin): anchored in block 960309 (2026-07-30T20:35:49Z), 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/DEF055830302.
Matthäus-Passion, BWV 244, Pt. 1: No. 12, Recit. Wiewohl mein Herz in Tränen schwimmt (Soprano)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9eabac32d7cf6e4b404db4ad5dd5602848ffe2249bfed1a6e9194df53a8c5dc2. Chain 2 (Bitcoin): anchored in block 960337 (2026-07-31T02:51:48Z), 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/DEF055830327.
Matthäus-Passion, BWV 244, Pt. 1: No. 13, Aria. Ich will dir mein Herz schenken (Soprano)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd9761a2fb19d226b809c2123e70f9b7d8b4cbcd89a893ae6479a313110e4bb65. 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/DEF055830328.
Die Schöpfung, Hob. XXI:2, Pt. 1: No. 4, Solo. Mit Staunen sieht das Wunderwerk – Chorus. Und laut ertönt aus ihren Kehlen
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8b70c2877cbdd86f3bef042fb4c81482042f508586b670d3c4abe92decb439ba. 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/DEF055530705.
Die Schöpfung, Hob. XXI:2, Pt. 1: No. 5, Recit. Und Gott sprach: Es sammle sich das Wasser
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5a45249c52adf09aa4de417c8746ad97ff4e62061b5d0a67507beefcd25c5b8d. Chain 2 (Bitcoin): anchored in block 960456 (2026-07-31T19:53:57Z), 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/DEF055530708.
Die Schöpfung, Hob. XXI:2, Pt. 1: No. 8, Aria. Nun beut die Flur das frische Grün
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2645fcabaae0145487a979abac8dd53631ef691f2c02b370ba6476c3577e98c8. 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/DEF055530709.
Die Schöpfung, Hob. XXI:2, Pt. 2: No. 15, Aria. Auf starkem Fittiche schwinget sich der Adler stolz
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb27de5d3b9b9ab8f980e07c152b19b67fd5c28d9f6738caeb4abf01a226876f0. 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/DEF055530716.
Die Schöpfung, Hob. XXI:2, Pt. 3: No. 30, Duet. Von deiner Güt', o Herr und Gott – Chorus. Gesegnet sei des Herren Macht
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc96dbedfbf5d09da200b38feb45806fb16292118ef587ae7bb26e457401107d5. 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/DEF055530728.
Messe solennelle de Sainte-Cécile, CG 56: II. Gloria
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbc25d07dd62f995a2949f09e676ff57d9506119449686c98258a304eeaca14cf. 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/DEF056501064.
Brahms: Liebeslieder-Walzer; Neue Liebeslieder-Walzer
Liebeslieder Waltzes, Op. 52: No. 1, Rede, Mädchen, allzu liebes
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x292d1835e83d20ee79efaa989793ef06ef1526f4076dc0f28e4bbe00f7d3aa03. Chain 2 (Bitcoin): anchored in block 960494 (2026-08-01T01:44:32Z), 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/DEF056230101.
Schubert, Brahms, Strauss, Wolf, Reger: Lieder; Hindemith: 3 Geistliche Motetten; Egk: Quattro canzoni
Wolf: Mörike Lieder; Italienisches Liederbuch (selections)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xabdfdd799e567c0cd5a06f9c7ce241a9385973f69feb3bd9ee9e0649bc860c7c. 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/DEF055902650.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5b86a9fa4f11e1e840ea7f2cdde7e68ecdd978ad6de09999bd3b1401c564cae8. 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/DEF055902660.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb3efa34cf1b738031f5150a867cc1a5b47f5a6bf55d6cbe7bbf48d627d7ab899. 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/DEF055902710.
Mörike-Lieder: No. 35, Frage und Antwort
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb6ff591d64997bf5192705a2d881780f5ccf894213df037536f24d77a082233c. Chain 2 (Bitcoin): anchored in block 960376 (2026-07-31T09:09:19Z), 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/DEF055902750.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa3b66efd200a70405799d0fa26d8d57482adbb858a2ba5d6ae48096c3d8a4685. 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/DEF055902760.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd8611c6acfccf427ebfd6fb0492cb09a180fa9d993cff4bd474bc7354b508555. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF055902800.
J.S. Bach: Cantata BWV 202; Respighi: Il tramonto; Mozart: Divertimento K. 138, Così fan tutte (arias)
Giulio Cesare, HWV 17, Act II: V'adoro, pupille
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1daa8b77c9ac885a32e7215e2318b88f12b8ce9b19ce6b754a0846b743f96562. 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/DEF056030102.
Irmgard Seefried sings Beethoven & Richard Strauss
Brahms, Richard Strauss, Cornelius: Lieder
St. Matthew Passion, Bwv 244: Pt. I: Chorus. Kommt, ihr Tochter, helft mir klagen (Chorus)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5f8b524c9d2e2dde2afa0eecff4d02711ae5088615307f7475b466ab4271a3ff. 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/DEAD61200801.