Klaus Hirte (28 December 1937 – 15 August 2002) was a German operatic baritone. Life Training Born in Berlin, Hirte grew up in Calw, learned the profession of tool and die maker and occasionally
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 0x9e423867bcc7d3d9c082e276784164539bf34a95692d333859081265ec2f0387. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/61740333-1204-4175-8e52-7d39e26d57d0.json and https://artists.proofprofile.net/proofs/artist/61740333-1204-4175-8e52-7d39e26d57d0.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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 0x02667d2027ad6113bed965a60c429e8592e474ed6ab9d69c7c4ad53e23843743. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/DEF056830101.
Le nozze di Figaro, K. 492, Act I: No. 2, Duet. Se a caso madama la notte ti chiama
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x426020da033afc6eab469abdbd9fd2851f00e4e5dadbbe4beae592895303f519. Chain 2 (Bitcoin): anchored in block 960125 (2026-07-29T15:38:18Z), 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/DEF056830103.
Le nozze di Figaro, K. 492, Act I: No. 3, Se vuol ballare, signor Contino
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2b939f0db984ff936a0ec2a3b6a9d94030abdcca0307e4900412fe7ee9abdac0. Chain 2 (Bitcoin): anchored in block 960207 (2026-07-30T04:47:22Z), 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/DEF056830124.
Le nozze di Figaro, K. 492, Act I: No. 4, La vendetta, oh, la vendetta!
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x10c46cc80a7b134a5b027109f170b3413dc759690c3982face2228626be21163. Chain 2 (Bitcoin): anchored in block 957073 (2026-07-07T18:39:05Z), 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/DEF056830105.
Le nozze di Figaro, K. 492, Act I: No. 6, Non so più cosa son, cosa faccio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x253c992e590ae298e62321882ea2fbfa093396a26013da6819c88dd73222ff7d. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF056830106.
Le nozze di Figaro, K. 492, Act I: No. 10, Non più andrai
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf58e12568caad2508140870c3f015e1bc72d866858d6a508b191066a47d478c7. Chain 2 (Bitcoin): anchored in block 959100 (2026-07-22T05:29:55Z), 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/DEF056830108.
Le nozze di Figaro, K. 492, Act II: No. 11, Porgi amor
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x99d3c17558ae6002f7e874bf92541a74bf6250510695503e2bf95b4365304798. Chain 2 (Bitcoin): anchored in block 957075 (2026-07-07T18:50:38Z), 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/DEF056830109.
Le nozze di Figaro, K. 492, Act II: No. 12, Voi che sapete
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9abdef85adf9912748223a2c4e1a5e70b32c807391100d0aa5775ad7836117ce. 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/DEF056830110.
Le nozze di Figaro, K. 492, Act II: No. 13, Venite inginocchiatevi
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x68b39513751dd2644e860dbc0311ebd4c130003d5b97e0c5dd725145dc97e21e. Chain 2 (Bitcoin): anchored in block 960193 (2026-07-30T02:05:19Z), 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/DEF056830111.
Le nozze di Figaro, K. 492, Act III: No. 18, Vedrò mentr'io sospiro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbb2181107f648bba1f6a0a26a34646262b47d637dcb3abd3171e1617e82e67a0. Chain 2 (Bitcoin): anchored in block 960240 (2026-07-30T09:57:33Z), 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/DEF056830184.
Le nozze di Figaro, K. 492, Act III: No. 20a, E Susanna non vien!
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ccfffce231989b5d446f7d6f2d4a0b75d27e6ddba5ad829ed9870b8fc1f308f. Chain 2 (Bitcoin): anchored in block 960203 (2026-07-30T03:35:13Z), 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/DEF056830160.
Le nozze di Figaro, K. 492, Act III: No. 20b, Dove sono i bei momenti
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc1960a14e1c150391f9597e7d7e5a5581498b7ea3ce1ff51ca80eef52c1b02a1. 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 via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEF056830161.
Le nozze di Figaro, K. 492, Act III: No. 21, Sull' aria... Che soave zeffiretto "Letter Duet"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2571e35f8bb7ddffa9fbbbdace6d7387632712a251a3e5904657b7624150fce7. Chain 2 (Bitcoin): anchored in block 953536 (2026-06-13T17:25:41Z), 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/DEF056830114.
Le nozze di Figaro, K. 492, Act IV: No. 24, L'ho perduta, me meschina
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0e5da1bb258ab204e7fcf28ed470e5c72f51b0ef3dd090f60a14a94ecfd622ba. Chain 2 (Bitcoin): anchored in block 960121 (2026-07-29T15:22:21Z), 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/DEF056830115.
Le nozze di Figaro, K. 492, Act IV: No. 27, Aprite un po' quegl' occhi
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x334378258061b55b4069e4cc0a1d25a191b442129e487e7f96d8a9e2ae183910. Chain 2 (Bitcoin): anchored in block 960144 (2026-07-29T21:09:47Z), 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/DEF056830175.
Le nozze di Figaro, K. 492, Act IV: No. 28a, Giunse alfin il momento
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe8311c5ac35fad9d67d1d530630329757cb4c2fbd44b835415463a71239f6b43. 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/DEF056830177.
Le nozze di Figaro, K. 492, Act IV: No. 28b, Deh vieni, non tardar
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf6cea390ce33f31f21654a0adc765f018e9841f581fc4709438de24fa0e8df9f. Chain 2 (Bitcoin): anchored in block 960273 (2026-07-30T15:42:38Z), 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/DEF056830178.
Le nozze di Figaro, K. 492, Act IV: No. 29e-g, Finale. Gente, gente, all'armi... Questo giorno di tormenti
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1cb0326f164ec3447479141e880d428d2b6c66508e3bf805045c3dc56d687c35. Chain 2 (Bitcoin): anchored in block 960166 (2026-07-29T23:39:29Z), 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/DEF056830118.
Die Meistersinger von Nürnberg / Act 1: "Da zu dir der Heiland kam"
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9dcd4da731241de06facad56da93069cbb07fd4f3eebdb5cd6f959c689604798. Chain 2 (Bitcoin): anchored in block 960478 (2026-07-31T23:30:38Z), 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/NLA507401167.