Gerd Zacher (6 July 1929 – 9 June 2014) was a German composer, organist, and writer on music. He specialized in contemporary compositions, many of which feature extended techniques, and are written in
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 0xd9aed1b3c2762edb71b3f81ab95245158aa47b68bd13d09c1967475cbefdc279. Chain 2 (Bitcoin): anchored in block 954729 (2026-06-21T18:16:07Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/f8a3eab7-f0c5-4790-ae79-ea4482c21abf.json and https://artists.proofprofile.net/proofs/artist/f8a3eab7-f0c5-4790-ae79-ea4482c21abf.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Kagel: Fantasy / Allende-Blin: Sonoritée / Ligeti: Volumina; Étude No. 1 "Harmonies"
Gerd Zacher: Event(ualitie)s – Solo and Duo Compositions
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 0x01da1b641c69912e47c046bf6d6bdf3f16bd8f2d30897975544ec5de0e876845. 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/SEWDL0739003.