Hans Dulfer
type: MusicGroup
description: Hans Dulfer (born 28 May 1940) is a Dutch jazz musician who plays tenor saxophone. Biography thumb|Hans Dulfer (left) and Candy Dulfer (center) in 2022 Hans Dulfer was born in 1940 in Amsterdam. Hi
popularity: 13
followers: 3477
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  value: 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
subject of: OpenTimestamps Proof of Existence
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album: The Morning After the Third
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  date published: 1970-01-01
album: Candy Clouds
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  date published: 1970-01-01
album: El Saxofon
  type: MusicAlbum
  date published: 1971-01-01
album: Big Boy
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  date published: 1994-01-01
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      date published: 1994-01-01
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    additional property: OTSVerifyInstructions
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    subject of: OpenTimestamps Proof of Existence
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      date published: 2026-07-19T09:51:44Z
    audio: Big Boy
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  track: Streetbeats
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    by artist: Hans Dulfer
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      date published: 1994-01-01
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      value: 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
    subject of: OpenTimestamps Proof of Existence
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      date published: 2026-07-19T00:50:09Z
    audio: Streetbeats
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  track: Mickey Mouth
album: Dig!
album: Skin Deep
album: Papa's Got A Brand New Sax (Live)
album: El Saxofon Part 2
album: The Formative Years '68 - '98
album: I Didn't Ask
album: Jazz In Paradiso
album: Big Boy, Dig Skin Deep (The Remixes 1994-1999)
album: Three Random Singles (Remastered)
album: LIVE IN PARADISO
album: EXPRESS DELAYED
track: Candy Clouds Pt 2

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Mickey Mouth
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duration: PT4M43S
duration ms: 283800
explicit: false
by artist: Hans Dulfer
in album: Big Boy
  type: MusicAlbum
  date published: 1994-01-01
isrc code: NLA279400607
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additional property: OTSVerifyInstructions
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  value: 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
subject of: OpenTimestamps Proof of Existence
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  date published: 2026-07-05T10:01:46Z
audio: Mickey Mouth
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Dig!
type: MusicAlbum
date published: 1996-01-01

Skin Deep
type: MusicAlbum
date published: 1998-01-01

Papa's Got A Brand New Sax (Live)
type: MusicAlbum
date published: 1998-01-01

El Saxofon Part 2
type: MusicAlbum
date published: 2000-01-01

Skin Deep
type: MusicAlbum
date published: 2003-01-01

The Formative Years '68 - '98
type: MusicAlbum
date published: 2010-01-01

I Didn't Ask
type: MusicAlbum
date published: 2010-01-01

Jazz In Paradiso
type: MusicAlbum
date published: 2010-01-01

Big Boy
type: MusicAlbum
date published: 2010-01-01

Big Boy, Dig Skin Deep (The Remixes 1994-1999)
type: MusicAlbum
date published: 2021-01-29

Three Random Singles (Remastered)
type: MusicAlbum
date published: 2021-05-14

LIVE IN PARADISO
type: MusicAlbum
date published: 2021-07-28

EXPRESS DELAYED
type: MusicAlbum
date published: 2022-01-26

Candy Clouds Pt 2
type: MusicRecording
duration: PT6M46S
duration ms: 406625
explicit: false
by artist: Hans Dulfer
in album: Spiritual Jazz, Vol. 2: Europe
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  date published: 2012-02-13
isrc code: GBCTF1000194
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additional property: OTSVerifyInstructions
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  value: 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
subject of: OpenTimestamps Proof of Existence
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  date published: 2026-07-08T03:20:19Z
audio: Candy Clouds Pt 2
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