John Grant Sangster (17 November 1928 – 26 October 1995) was an Australian jazz composer, arranger and multi-instrumentalist. He is best known as a composer although he also worked with Graeme Bell, H
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 0xcdfa24ccb8d101a332732b09f4d61817bb28d0c4e7bb48455f1c1ccac276a45f. Chain 2 (Bitcoin): anchored in block 954065 (2026-06-17T08:10:43Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/564982d2-4079-420a-b715-e7b2c88176e3.json and https://artists.proofprofile.net/proofs/artist/564982d2-4079-420a-b715-e7b2c88176e3.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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 0x38843496e1ec84b050af6904dc817c48ca39c7b9f3f0fbbade3cf39aa7dad2b1. Chain 2 (Bitcoin): anchored in block 959037 (2026-07-21T16:59:47Z), 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/AUOM01902788.
The Last Will and Testament of John Sangster
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xc46838cc67d6212bb2672dc1b71bbf18c5663dde95ad7febf131f810d9ce5c46. Chain 2 (Bitcoin): anchored in block 958331 (2026-07-16T21:55:37Z), 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/AUOM01902927.
Jazz Music Series 2: Requiem (for a loved one)
Jazz Music Series 1: Don't mean a thing if it ain't got that doo-wup