Henri Sigfridsson (born 1974) is a Finnish classical pianist. Studies Born in Turku, Sigfridsson began his musical studies in his native hometown conservatory. He then attended Erik T. Tawaststjern
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 0x56e6fc5336f7b9107b1844a304c7f5b38db5b7fdb4087a7aad52a0b1b466e82d. Chain 2 (Bitcoin): anchored in block 954705 (2026-06-21T13:42:37Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/ec67c2a7-1388-4914-80b7-e685b72bd4d1.json and https://artists.proofprofile.net/proofs/artist/ec67c2a7-1388-4914-80b7-e685b72bd4d1.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Korngold: Violin Concerto in D Major, Op. 35 (Live)
Korngold: String Sextet, Op. 10 & Suite, Op. 23
Short Stories - A Collection of Romantic Violin Pieces
Hakola, K.: Piano Concerto / Sinfonietta
Sibelius, Grieg & Scriabine: Edition Klavier-Festival Ruhr, Vol. 34
Palmgren: Piano Sonata in D minor, Op. 11
Sibelius: Symphonies Nos. 2 & 5 (Piano Transcriptions)
Pelleas och Melisande (Pelleas and Melisande), Op. 46 (version for piano): No. 5. Melodrama in Act III Scene 4, "Pastorale"
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 0x00f6d7e747e7d5ca3736cbbcd26b8d6cdf96258a6a848b45df0321e5ad85ec11. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), 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/DEA550714352.
Belshazzar's Feast Suite, Op. 51 (version for piano): II. Solitude
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xed71ffe1471bc1ce11fe81e277325d7fe1f287fd95413c09b9674d681111a3ae. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/DEA550714361.
Rachmaninov: Piano Concertos Nos. 2 and 3
Trails Of Creativity - Music From Between The Wars For Violin And Piano
Franz Xaver Mozart: Piano Concerto No. 1 And 2
Korngold: String Quartets Nos. 1-3 / Piano Quintet, Op. 15
Rarities of Piano Music at »Schloss vor Husum« from the 2013 Festival
Matvejeff: Ad astra & Cello Concerto - Linkola: Piano Concerto No. 1