Marcel Cordes (born Kurt Schumacher, 11 March 1920 – 26 November 1992) was a German baritone in opera and concert. He was regarded as a leading baritone of German origin for Italian opera in the 1950s
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 0x6fe4902dbf7e088fca777d618012619c74b00351ea74a0ab846defe02fb0cd9d. Chain 2 (Bitcoin): anchored in block 954513 (2026-06-20T06:31:18Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/9d0b6360-791e-472a-9cc6-8a9d08e57fb0.json and https://artists.proofprofile.net/proofs/artist/9d0b6360-791e-472a-9cc6-8a9d08e57fb0.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
The Blackest Bass: Gottlob Frick Portrait
Die Entführung aus dem Serail, K. 384: Wer ein Liebchen hat gefunden
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 0xeddb3a89cdf90308656b4f16a8dd65c716ede776ca0e8a2ec2ec31a831fe11be. 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/DEAD61804701.
Die Zauberflöte, K. 620: O Isis und Osiris
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xff514413cd1be0a819665a33e8a16fb849ecbf3a8b4d42260d92f27e431f3d9b. 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/DEAD61804704.
Jägers Liebeslied (Arr. for Bass & Orchestra)
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Richard Strauss: Feuersnot, Op. 50, TrV 203 (Bayerische Staatsoper Live)
Schumann: Symphony No. 3 in E-Flat Major, Op. 97 "Rhenish": I. Lebhaft
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Schumann: Symphony No. 3 in E-Flat Major, Op. 97 "Rhenish": II. Scherzo. Sehr mäßig
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x29349ec06c457a88d778f23355f10010d10e3b4107b95cf67d1539ce27d50d76. 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/GBAYC0200345.
Schumann: Symphony No. 3 in E-Flat Major, Op. 97 "Rhenish": III. Nicht schnell
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Schumann: Symphony No. 3 in E-Flat Major, Op. 97 "Rhenish": IV. Feierlich
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8d9227a37a1b641a5d7610c4da0dd69c0d52605f516e03eccc714d85852cf070. 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/GBAYC0200347.
Schumann: Symphony No. 3 in E-Flat Major, Op. 97 "Rhenish": V. Lebhaft
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x38afc21783d46170e95726b6a1d3889c5fa7faab34a98c95e51e05177cf12c4a. 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/GBAYC0200348.
Tchaikovsky: Swan Lake, Op. 20: Introduction
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7a755f807f7250f3669f1ac12b0dbbb086b1a4c041909bdb4c0f3fc280d0548a. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBAYC9401929.
Tchaikovsky: Swan Lake, Op. 20, Act 1: No. 2, Waltz
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Tchaikovsky: Swan Lake, Op. 20, Act 2: No. 10, Scene. Moderato
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9457ecc39592982d133bddb46967ae77ada328035c686fe157d446ed48fceafd. 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/GBAYC9401951.
Tchaikovsky: Swan Lake, Op. 20, Act 2: No. 13d, Dance of the Swans. Dance of the Little Swans
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe040b4b4c3514d80864a8b127c5cfcd83f030ce95f3fe7b304ce51ae00a3e1da. 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/GBAYC9401958.
Beethoven: Symphony No. 5 in C Minor, Op. 67: I. Allegro con brio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdb3ea75f6f3425ef93e743d3e7e54148baac8077218a6888810a7ae242d33b62. 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/GBAYC9101264.
Mozart: Piano Concerto No. 21 in C Major, K. 467: II. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x308d82b4b2fdeafa40ca7e8ab70b1c9853c330e6b0c103f2b2f277322f1279fc. 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/GBAYC0400114.
North German Radio Philharmonic Orchestra
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Im Reich der Operette, Vol. 5 (Favoriten - Raritäten - Entdeckungen)
Giuditta: Freunde, das Leben ist lebenswert
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Gräfin Mariza: Wenn es Abend wird (Grüß mir mein Wien)
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Brothers Grimm's Fairy Tales in Operas: Die Kluge
Orff: Der Mond: "Verzeiten gab es ein Land" (Erzähler)
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Orff: Der Mond: "So brachte Petrus die Toten zur Ruh" (Erzähler)
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Orff: Der Mond: "Ach, da hängt ja der Mond!" (Kleines Kind, Chor)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x34049d8c9d3b8f564a0e0a64b5d5666e436d4a7d86dc8445c75879a09a4bc115. Chain 2 (Bitcoin): anchored in block 960117 (2026-07-29T14:28:24Z), 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/GBAYC5700101.
Orff: Die Kluge: "Oh hätt' ich meiner Tochter nur geglaubt!" (Bauer)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9bcfd1ceda6f289be602ce9f7d4099a530e97d42dd39a6f96fb698ac2235d9a9. Chain 2 (Bitcoin): anchored in block 960422 (2026-07-31T15:27:29Z), 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/GBAYC5600170.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc6701371223c6b2f11d529a75a3288cc61dfc3a2217e78e6be8c7a1d2d202ae2. 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/GBAYC5700100.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x34049d8c9d3b8f564a0e0a64b5d5666e436d4a7d86dc8445c75879a09a4bc115. Chain 2 (Bitcoin): anchored in block 960344 (2026-07-31T04:14:58Z), 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/GBAYC5700101.
Orff: Carmina Burana; Die Kluge (Highlights)
Es war einmal... Grimms Märchen in der Musik
Fritz Wunderlich - Der große deutsche Tenor
Handel: Serse, HWV 40, Act 1, Scene 1: Arioso. "Ombra mai fù" (Serse)
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Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x46e7e9ef0508cd7aa9be297faaa0951453c97e0ec6a3e5d6c3d8292b69735f8a. Chain 2 (Bitcoin): anchored in block 960258 (2026-07-30T12:45:34Z), 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/DEA340000807.
Eine Nacht in Venedig, Act I: "Komm' in die Gondel"
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Wunderlich, Fritz: Rarities From Opera and Operetta
Fritz Wunderlich: Die Electrola-Querschnitte 1960-63
Leoncavallo: Der Bajazzo (Pagliacci - Sung in German)
Cherubini: Der Wasserträger (Sung in German)
Requiem in D Minor, K. 626: III. Seq. 6, Lacrimosa
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Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x313983126961f92cc38ede44b7a1144bb723982947a149b5ad6fc0d09563d530. 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/DEA340700580.
Smetana: Die verkaufte Braut, Act 1: Chor. "Seht am Strauch die Knosepn springen" (Chor, Marie, Hans)
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Milestones of a Legendary Conductor: Wolfgang Sawallisch, Vol. 10
Dokumente einer Sängerkarriere - Marcel Cordes
Holzschuhtanz: Zar und Zimmermann - Highlights (Inspiration)
Lortzing: Zar und Zimmermann, Act III: 'Holzschuhtanz'
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