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 0x595b307f3c766b86c2f8e32f98815f296f72861579fdf24716729afc78bcdd32. Chain 2 (Bitcoin): anchored in block 954342 (2026-06-19T03:22:39Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/90521d90-bd91-4339-90c6-1827066cc8ac.json and https://artists.proofprofile.net/proofs/artist/90521d90-bd91-4339-90c6-1827066cc8ac.ots, the client at https://opentimestamps.org runs `ots verify -f record.json proof.ots`.
Strauss, R.: Horn Concertos Nos. 1 and 2 / Schoeck, O.: Horn Concerto, Op. 65 / Pfluger, H.-G.: Horn Concerto
Horn Recital: Joy, Andrew - Haydn, J. / Rosetti, A. / Punto, G. / Cherubini, L. / Danzi, F.
Horn Recital: Joy, Andrew - Haydn, F.J. / Rosetti, A. / Punto, G. / Cherubini, L. / Danzi, F.