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
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xeddb3a89cdf90308656b4f16a8dd65c716ede776ca0e8a2ec2ec31a831fe11be. 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/DEAD61804701.
Richard Strauss: Feuersnot, Op. 50, TrV 203 (Bayerische Staatsoper Live)
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 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/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 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/GBAYC0200348.
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 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/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
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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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xec41d25ff32191fa9f164f0b6791030fed9a249d3ad4a41acd73278179a2c123. 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/HKI191525002.
Brothers Grimm's Fairy Tales in Operas: Die Kluge
Orff: Der Mond: "So brachte Petrus die Toten zur Ruh" (Erzähler)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc6701371223c6b2f11d529a75a3288cc61dfc3a2217e78e6be8c7a1d2d202ae2. 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/GBAYC5700100.
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.
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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Eine Nacht in Venedig, Act I: "Komm' in die Gondel"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf68e7cfce17f34afa95c931efef740031b8d0137844bc6c57d3c7be4c621b90b. 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/DEA340000829.
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)
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Smetana: Die verkaufte Braut, Act 1: Chor. "Seht am Strauch die Knosepn springen" (Chor, Marie, Hans)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x70c8e3d1aff11ccd4cd93b24108e1e7f371851f8e73a9233503120f95d4e3cb1. 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/DEA340700582.
Milestones of a Legendary Conductor: Wolfgang Sawallisch, Vol. 10
Dokumente einer Sängerkarriere - Marcel Cordes
Holzschuhtanz: Zar und Zimmermann - Highlights (Inspiration)