Albert Eric Maschwitz OBE (10 June 1901 – 27 October 1969), sometimes credited as Holt Marvell, was an English entertainer, writer, editor, broadcaster and broadcasting executive. Eric Maschwitz (left
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 0x8e016d193a36ba6cd9e519dc2a58f743dc2e4686a2d63f09382036db6dd612af. Chain 2 (Bitcoin): anchored in block 954066 (2026-06-17T08:11:48Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/5882ae93-b518-4aaf-b6d3-eb12c1fa529d.json and https://artists.proofprofile.net/proofs/artist/5882ae93-b518-4aaf-b6d3-eb12c1fa529d.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
A Nightingale Sang in Berkeley Square (Arr. Ruairi Bowen)
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
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd66fc68c78bf6f17bd6cefcdb55350121fd28c5152c49199de3f91abba3c24a5. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/GBMY51400604.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x540f5ba51252585c86f9f5d2fb4dc9b0a9cb76a493499f0fe74fcc0b8e0365a2. Chain 2 (Bitcoin): anchored in block 960500 (2026-08-01T03:13:03Z), 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/USSM18600250.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1059ed22eee01893e803de214668b15483a0d3ecb05c8432e1f6251e99bc5ffb. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/GBAYE0300215.
The Golden Age of Light Music: The 1940s
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8cc2fdaf485d888049b76bfc3c8b1267c9b0091e5000a65304d0262c22bc0a3d. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), 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/CH6630450211.
C:3 A Nightingale Sang in Berkeley Square
Piano Exam Pieces 2025 & 2026, ABRSM Grade 8
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x72b0ae5c8951a9f67e4065cebe9397de8a7950293575017fbaa70a68835daf07. 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/GBEYQ2458335.
B:3 A Nightingale Sang in Berkeley Square
Violin Exam Pieces from 2024, ABRSM Grade 5
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x1bbdf96a72a4ea71f0ef855b9f482789847d603eae5b8e46e01570925f666677. 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/GBEYQ2392706.
B:3 A Nightingale Sang in Berkeley Square - accompaniment
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc2b8a6a87eb4371ad9402f93ac60d305730a1e2ce3892808c7612b0bd64f3f66. Chain 2 (Bitcoin): anchored in block 957073 (2026-07-07T18:39:05Z), 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/GBEYQ2392714.