Leopold Ludwig (12 January 1908 – 25 April 1979) was a German conductor active mainly in Austria and Germany from the 1930s through the 1970s. He was principal conductor of the Oldenburgisches Staatst
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 0x280e75c6e330dcb2099e72a25bc9341b974e7e994abf34567560d41419cc9f1c. Chain 2 (Bitcoin): anchored in block 953648 (2026-06-14T15:20:52Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/4529c0ca-136a-4a72-a3eb-9da15ab11dce.json and https://artists.proofprofile.net/proofs/artist/4529c0ca-136a-4a72-a3eb-9da15ab11dce.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Irmgard Seefried (Recorded in 1944-1967)
J.S. Bach: Concerto for 2 Harpsichords in C Major, BWV 1061 - Beethoven: Piano Concerto No. 5 in E-Flat Major, Op. 73
Hindemith: Cardillac; Mathis der Maler (Excerpts)
Verdi: Macbeth (Live Recordings 1950) [Sung in German]
Brahms: Quintette pour clarinette et cordes & Variations sur un thème de Haydn (Mono Version)
Beethoven: Symphonie No. 7, Op. 92 - Die Weihe des Hauses
Piano Concerto No. 4 in G Major, Op. 58: I. Allegro moderato
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 0x498af330add84e85e4e0dc781969967203141dc6876fa8b01ebad8127a540230. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CZH401105978 — a six-check JSON result.
Beethoven: Piano Concerto No. 5 "Emperor" - Rachmaninoff: Piano Concerto No. 3
Piano Concerto No. 5 in E-Flat Major, Op. 73 "Emperor": II. Adagio un poco moto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdf9ba606cfe31409e278acbed59df7ee2187836d26a9b1902fa510d80fe885bf. Chain 2 (Bitcoin): anchored in block 960348 (2026-07-31T05:17:02Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEL112000617 — a six-check JSON result.
Milestones of a Piano Legend: Shura Cherkassky, Vol. 4
Schubert: Symphony No. 8 "Unfinished" - Mozart: Symphony No. 40 (Transferred from the Original Everest Records Master Tapes)
Tchaikovsky: Concerto Op. 23 No. 1 - Liszt: Concerto in A Minor No. 2
Beethoven : Concerto pour Piano No. 5 "Emperor"
Hans Hotter "the Wotan of the Century" At His Best, Vol. 4
Beethoven: Piano Concertos 4 & 5 "The Emperor"
Piano Concerto No.5 in Eb Major, Op. 73 "Emperor": I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x52713e5cf9e3ea3cac97f0c4b2a2c84f4b2fbf4788a935d5792e93b6b85da69b. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBJ2F1110519 — a six-check JSON result.
Piano Concerto No.5 in Eb Major, Op. 73 "Emperor": II. Adagio un Poco Mosso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x26c78b909125d1983a6b9243721ee62c75ca934865beb34ab19d17f6b8cff51e. Chain 2 (Bitcoin): anchored in block 960138 (2026-07-29T19:35:34Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/GBJ2F1110520 — a six-check JSON result.
Carl Maria von Weber: Abu Hassan (Opera Bouffe - Comic Opera)
Chopin: Konzert für Klavier und Orchester Nr.2 f-moll op.21 / Polonaisen Nr.6 op.53 & Nr. 3 op. 40 Nr.1
Piano Concerto No. 2 in F minor, Op. 21: 1. Maestoso
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa7a3356aafa95b1856dbf88ae297c0aff5b1ab5b524aecd2455e253d7f814e4d. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF056200991 — a six-check JSON result.
Piano Concerto No. 2 in F minor, Op. 21: 2. Larghetto
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1a5e833fc209b6a39f19786d335627ad257ab4e433e80710fe9e8273c70e4693. Chain 2 (Bitcoin): anchored in block 960389 (2026-07-31T10:20:10Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF056200992 — a six-check JSON result.
Polonaise No. 3 in A Major, Op. 40 No. 1 "Military"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x168ef97a03b2ed934112ec810365f44ddc13ef6fb71407e3d92d68e0d68ac9c5. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF056201010 — a six-check JSON result.
Cornelius, P.: Barber of Bagdad (The) (Schwarzkopf, Gedda, Leinsdorf) (1956) / Weber, C.M.: Abu Hassan (Schwarzkopf, Witte, Ludwig) (1944)
Legenden Des Gesanges, Vol. 7: Astrid Varnay (1954-1955)
Vocal Recital: Schwarzkopf, Elisabeth - Verdi, G. / Loewe, C. / Weber, C.M. Von / Mozart, W.A. / Bach, J.S. / Handel, G.F. / Beethoven, L. Van
Martha Mödl Sings Händel, Purcell, Gluck, Mussorgsky and Others
Wagner: Die Walkure Act 3 Scene 3 - Die Fliegende, Act 2 - Deinen Leichten Sinn - Leb' Wohl, du Kuhnes, Herrliches Kind!
Dvorak: Symphony No. 9 in E Minor, Op. 95 "From the New World" (Transferred from the Original Everest Records Master Tapes)
Symphony No. 9 in D Major: IV. Adagio, Sehr langsam und noch zurückhaltend
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7bf34464a0c2c424369ffe51ff587c46bc6a1ae8de4ee6cf2ac49f8de5a962e5. Chain 2 (Bitcoin): anchored in block 960108 (2026-07-29T13:09:35Z), 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CAM460770472 — a six-check JSON result.
Symphony No. 40 in G Minor, K.550, I. Molto Allegro
Uplifting Classical - Music to energize your mood
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x12175ff2176a221847102f0f4bb96d5a7d7ace7f60d400c7e60cf6500571397f. 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 at https://artists.proofprofile.net/api/v1/bot/ots/verify/track/CAM460870171 — a six-check JSON result.