Karel van Steenhoven (born November 1958 in Voorburg) is a Dutch recorder player and composer. Biography Starting with a green plastic instrument when he was four years old, Steenhoven began to study
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 0x1892b2ce0b32d662d7bce1242557592c3f80ea23cfe33f7383f3f29d7be63097. Chain 2 (Bitcoin): anchored in block 954587 (2026-06-20T19:10:41Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/bc114824-5518-4d5d-9a7b-b418489573e8.json and https://artists.proofprofile.net/proofs/artist/bc114824-5518-4d5d-9a7b-b418489573e8.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Arias for Soprano and Oboe from Cantatas by J.S. Bach
Harpsichord Concerto No. 6 in F Major, BWV 1057: III. Allegro assai
Johann Sebastian Bach: Harpsichord Concertos (Schornsheim, New Bach Collegium Musicum, Glaetzner)
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 0xdb0f6cbd481677e41c88e61dc39c2950bfb1a8e8eaec1a6069721b729f2b1c94. Chain 2 (Bitcoin): anchored in block 956349 (2026-07-02T11:34:59Z), 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/DES380004596.