Musica ficta (from Latin, "false", "feigned", or "fictitious" music) was a term used in European music theory from the late 12th century to about 1600 to describe pitches, whether notated or added at
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 0xf0461193cb86afd0c6f036342586f8f67f8882cc939afd6e0362f39db6513a89. Chain 2 (Bitcoin): anchored in block 953827 (2026-06-15T19:59:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ed53766b-ed92-455f-8eb8-4835f3d65a3b.json and https://artists.proofprofile.net/proofs/artist/ed53766b-ed92-455f-8eb8-4835f3d65a3b.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Tomas Luis De Victoria: Officium Defuntorum - Musica Ficta - Raul Mallavibarrena
Vocal and Chamber Music (17Th-18Th Centuries) - Herrera, J. De / Cascante, J. / Cabanilles, J. / Marin, J. / Sanz, G. / Falconieri, A.
Cancioner Deturin: Romances, villancicos y canciones del Siglo de Oro - Musica Ficta - Raul Mallavibarrena
Esa Noche Yo Baílá - Feast and Devotion in High Peru of the 17th Century
Del Mar del Alma : Music and Poetry In Colonial Bogota 17th-18th c.