Marc Engelhardt is a German bassoonist. From 1976 to 1982, he studied with Günter Pfitzenmaier in Cologne and from 1982 to 1986, with Klaus Thunemann in Hannover. Engelhardt is an alumnus of the Germ
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 0x80df3f82cf53585f76c407cf4979c5fee76c412c7f6d3e25889d5b1ac00558fc. Chain 2 (Bitcoin): anchored in block 953770 (2026-06-15T09:50:11Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/a310812a-3dad-4cc5-9697-b552a23519a7.json and https://artists.proofprofile.net/proofs/artist/a310812a-3dad-4cc5-9697-b552a23519a7.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Trumpet Concerto in E-Flat Major: II. Andante
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 0x1fa000a98f45fa3547d3a8011ec761d4838b046d5662ee720acf249c64514fa2. 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/DEA140639502.
Trumpet Concerto in E-Flat Major: III. Finale. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x93bfdb5b7323fd7f48875f598f235d136f00e305f3bbbde2cbb3da470ee797f7. 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/DEA140639503.
Concertino for Trumpet and Orchestra in C Major: I. Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x511339dbea4acc52a45da69f3975fa814c1165c65fcf2708784c7038c9c220c6. 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/DEA140639504.
Trumpet Concerto in E-Flat Major: I. Allegro
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0bd2095673fdc8bf9eff1f704133cde38e0a9cf6bd8230e53c75cbe82b8a5130. 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/DEA140639501.
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