Marcus Ullmann (born 1967) is a German classical tenor. Professional career Born in Dresden, Marcus Ullmann received his first musical training as a choir boy in the Dresdner Kreuzchor. He studied
{"copyright_id":"0xdbbf1f2d72bc023ffdf98fcbfa3855f23cd7ebbe3c053fabfd3e42a8a83674c3","name":"Marcus Ullmann","registered_at":"2026-06-14T11:13:44Z","symbol":"NIM0435191","token_address":"0x802ce60dbe0b3c4a21ddabb730f9fdba7fcfd7d8","type":"artist","uuid":"40a3da5a-d9f8-4cec-a63a-e65a3d4ad898"}
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 0xdbbf1f2d72bc023ffdf98fcbfa3855f23cd7ebbe3c053fabfd3e42a8a83674c3. Chain 2 (Bitcoin): anchored in block 953645 (2026-06-14T14:31:42Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/40a3da5a-d9f8-4cec-a63a-e65a3d4ad898.json and https://artists.proofprofile.net/proofs/artist/40a3da5a-d9f8-4cec-a63a-e65a3d4ad898.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Johann Sebastian Bach: Mass in B Minor, BWV 232