R.ef
type: MusicGroup
description: R.ef was a boyband trio in South Korea. Their main genres were K-pop and hip-hop. History In 1995, 21-year-old singer Lee Sung Wook (이성욱), 25-year-old rapper Park Chul Woo (박철우) and 21-year-old sing
popularity: 18
followers: 3510
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0x85ea734389f56cd13be9a12a11ac477a7de09ab3e3bafbc8bcf72db9ff71516b
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 953713
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/953713
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/84a01a76-f794-4f05-bc79-eec5e40200f9.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/84a01a76-f794-4f05-bc79-eec5e40200f9.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/84a01a76-f794-4f05-bc79-eec5e40200f9
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-15T00:33:41Z
additional property: OTSCanonicalRecord
additional property: OTSVerifyInstructions
  type: PropertyValue
  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
  type: DigitalDocument
  encoding format: application/vnd.opentimestamps.ots
  description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x85ea734389f56cd13be9a12a11ac477a7de09ab3e3bafbc8bcf72db9ff71516b. Chain 2 (Bitcoin): anchored in block 953713 (2026-06-15T00:33:41Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/84a01a76-f794-4f05-bc79-eec5e40200f9.json and https://artists.proofprofile.net/proofs/artist/84a01a76-f794-4f05-bc79-eec5e40200f9.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-15T00:33:41Z
album: Rave Effect!!
  type: MusicAlbum
  date published: 1995-03-01
album: Rave Effect
  type: MusicAlbum
  date published: 1995-03-01
album: Back To The Black
  type: MusicAlbum
  date published: 1996-04-01
  track: Walking through Mind
    type: MusicRecording
    duration: PT3M59S
    duration ms: 239086
    explicit: false
    by artist: R.ef
    in album: Back To The Black
      type: MusicAlbum
      date published: 1996-04-01
    isrc code: KRA341442839
    additional property: CopyrightID
    additional property: CopyrightStatus
      type: PropertyValue
      value: registered
    additional property: CopyrightRegisteredAt
      type: PropertyValue
      value: 2026-07-15T21:38:11+00:00
    additional property: CopyrightChainExplorerURL
      type: PropertyValue
      value: https://explorer.copyrightchains.com/tx/0xcadb3b717b3af419083970e82d9f2a75152637d5f320da1b64be019484d8fb56
    additional property: OTSHash
    additional property: OTSBitcoinBlock
      type: PropertyValue
      value: 958208
    additional property: OTSBitcoinBlockVerifyURL
      type: PropertyValue
      value: https://blockstream.info/api/block-height/958208
    additional property: OTSVerificationAPI
      type: PropertyValue
      value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/KRA341442839
    additional property: OTSTimestamp
      type: PropertyValue
      value: 2026-07-15T22:40:25Z
    additional property: OTSVerifyInstructions
      type: PropertyValue
      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
      type: DigitalDocument
      encoding format: application/vnd.opentimestamps.ots
      description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xcadb3b717b3af419083970e82d9f2a75152637d5f320da1b64be019484d8fb56. Chain 2 (Bitcoin): anchored in block 958208 (2026-07-15T22:40:25Z), 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/KRA341442839.
      date published: 2026-07-15T22:40:25Z
    audio: Walking through Mind
      type: AudioObject
      additional property: Tempo (BPM)
        type: PropertyValue
        value: 144.998
      additional property: Musical Key
        type: PropertyValue
        value: 1
      additional property: Mode (Major/Minor)
        type: PropertyValue
        value: 0
      additional property: Time Signature
        type: PropertyValue
        value: 4
      additional property: Danceability
        type: PropertyValue
        value: 0.636
      additional property: Energy
        type: PropertyValue
        value: 0.928
      additional property: Speechiness
        type: PropertyValue
        value: 0.047
      additional property: Acousticness
        type: PropertyValue
        value: 0.002
      additional property: Instrumentalness
        type: PropertyValue
        value: 0.015
      additional property: Liveness
        type: PropertyValue
        value: 0.291
      additional property: Valence (Positivity)
        type: PropertyValue
        value: 0.563
      additional property: Loudness (dB)
        type: PropertyValue
        value: -8.263
      additional property: Key Name
        type: PropertyValue
        value: C#
      additional property: Mode Name
        type: PropertyValue
        value: Minor
  track: Brilliant Love (Broken heart2)
    type: MusicRecording
    duration: PT3M49S
    duration ms: 229343
    explicit: false
    by artist: R.ef
    in album: Back To The Black
      type: MusicAlbum
      date published: 1996-04-01
    isrc code: KRA341442843
    additional property: CopyrightID
    additional property: CopyrightStatus
      type: PropertyValue
      value: registered
    additional property: CopyrightRegisteredAt
      type: PropertyValue
      value: 2026-07-03T00:23:13+00:00
    additional property: CopyrightChainExplorerURL
      type: PropertyValue
      value: https://explorer.copyrightchains.com/tx/0xa5b65ea0ac417bc0a25dc6acb50395a8bb9b840931b881c69476f0496b8870e0
    additional property: OTSHash
    additional property: OTSBitcoinBlock
      type: PropertyValue
      value: 956422
    additional property: OTSBitcoinBlockVerifyURL
      type: PropertyValue
      value: https://blockstream.info/api/block-height/956422
    additional property: OTSVerificationAPI
      type: PropertyValue
      value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/KRA341442843
    additional property: OTSTimestamp
      type: PropertyValue
      value: 2026-07-03T01:01:38Z
    additional property: OTSVerifyInstructions
      type: PropertyValue
      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
      type: DigitalDocument
      encoding format: application/vnd.opentimestamps.ots
      description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa5b65ea0ac417bc0a25dc6acb50395a8bb9b840931b881c69476f0496b8870e0. Chain 2 (Bitcoin): anchored in block 956422 (2026-07-03T01:01:38Z), 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/KRA341442843.
      date published: 2026-07-03T01:01:38Z
    audio: Brilliant Love (Broken heart2)
      type: AudioObject
      additional property: Tempo (BPM)
        type: PropertyValue
        value: 135.943
      additional property: Musical Key
        type: PropertyValue
        value: 9
      additional property: Mode (Major/Minor)
        type: PropertyValue
        value: 0
      additional property: Time Signature
        type: PropertyValue
        value: 4
      additional property: Danceability
        type: PropertyValue
        value: 0.622
      additional property: Energy
        type: PropertyValue
        value: 0.955
      additional property: Speechiness
        type: PropertyValue
        value: 0.053
      additional property: Acousticness
        type: PropertyValue
        value: 0.015
      additional property: Instrumentalness
        type: PropertyValue
        value: 0
      additional property: Liveness
        type: PropertyValue
        value: 0.156
      additional property: Valence (Positivity)
      additional property: Loudness (dB)
      additional property: Key Name
      additional property: Mode Name
album: Back To the Black
album: Memories In Fall
album: Second & Half
album: Free Ruff Eazy Flava III
album: Forever
album: The Last
album: It's R.ef
album: 왜이래
track: Love is difficult - Remix

Valence (Positivity)
type: PropertyValue
value: 0.408

Loudness (dB)
type: PropertyValue
value: -6.435

Key Name
type: PropertyValue
value: A

Mode Name
type: PropertyValue
value: Minor

Back To the Black
type: MusicAlbum
date published: 1996-04-01

Memories In Fall
type: MusicAlbum
date published: 1996-04-01

Second & Half
type: MusicAlbum
date published: 1996-09-01

Free Ruff Eazy Flava III
type: MusicAlbum
date published: 1997-01-01

Forever
type: MusicAlbum
date published: 1998-05-01
track: The Deaf Sky
  type: MusicRecording
  duration: PT4M19S
  duration ms: 259733
  explicit: false
  by artist: R.ef
  in album: Forever
    type: MusicAlbum
    date published: 1998-05-01
  isrc code: KRA341442860
  additional property: CopyrightID
  additional property: CopyrightStatus
    type: PropertyValue
    value: registered
  additional property: CopyrightRegisteredAt
    type: PropertyValue
    value: 2026-07-04T08:30:50+00:00
  additional property: CopyrightChainExplorerURL
    type: PropertyValue
    value: https://explorer.copyrightchains.com/tx/0x44e120bdb5623a98344318469b6d6aa308f302ae68b6148a1aa12ab9b6ca6bb1
  additional property: OTSHash
  additional property: OTSBitcoinBlock
    type: PropertyValue
    value: 956634
  additional property: OTSBitcoinBlockVerifyURL
    type: PropertyValue
    value: https://blockstream.info/api/block-height/956634
  additional property: OTSVerificationAPI
    type: PropertyValue
    value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/KRA341442860
  additional property: OTSTimestamp
    type: PropertyValue
    value: 2026-07-04T10:04:33Z
  additional property: OTSVerifyInstructions
    type: PropertyValue
    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
    type: DigitalDocument
    encoding format: application/vnd.opentimestamps.ots
    description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x44e120bdb5623a98344318469b6d6aa308f302ae68b6148a1aa12ab9b6ca6bb1. Chain 2 (Bitcoin): anchored in block 956634 (2026-07-04T10:04:33Z), 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/KRA341442860.
    date published: 2026-07-04T10:04:33Z
  audio: The Deaf Sky
    type: AudioObject
    additional property: Tempo (BPM)
      type: PropertyValue
      value: 138.697
    additional property: Musical Key
      type: PropertyValue
      value: 8
    additional property: Mode (Major/Minor)
      type: PropertyValue
      value: 0
    additional property: Time Signature
      type: PropertyValue
      value: 4
    additional property: Danceability
      type: PropertyValue
      value: 0.622
    additional property: Energy
      type: PropertyValue
      value: 0.945
    additional property: Speechiness
      type: PropertyValue
      value: 0.048
    additional property: Acousticness
      type: PropertyValue
      value: 0.107
    additional property: Instrumentalness
      type: PropertyValue
      value: 0.031
    additional property: Liveness
      type: PropertyValue
      value: 0.177
    additional property: Valence (Positivity)
      type: PropertyValue
      value: 0.493
    additional property: Loudness (dB)
      type: PropertyValue
      value: -7.48
    additional property: Key Name
      type: PropertyValue
      value: Ab
    additional property: Mode Name
      type: PropertyValue
      value: Minor

The Last
type: MusicAlbum
date published: 1999-01-01
track: Separation Formula
  type: MusicRecording
  duration: PT4M15S
  duration ms: 255831
  explicit: false
  by artist: R.ef
  in album: The Last
    type: MusicAlbum
    date published: 1999-01-01
  isrc code: KRA340911903
  additional property: CopyrightID
  additional property: CopyrightStatus
    type: PropertyValue
    value: registered
  additional property: CopyrightRegisteredAt
    type: PropertyValue
    value: 2026-07-21T23:04:22+00:00
  additional property: CopyrightChainExplorerURL
    type: PropertyValue
    value: https://explorer.copyrightchains.com/tx/0x8a7d3184c2e2860ef4e3d565462ea2506134c1b79e3ca2ff8e0e80836c8b75c1
  additional property: OTSHash
  additional property: OTSBitcoinBlock
    type: PropertyValue
    value: 959076
  additional property: OTSBitcoinBlockVerifyURL
    type: PropertyValue
    value: https://blockstream.info/api/block-height/959076
  additional property: OTSVerificationAPI
    type: PropertyValue
    value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/KRA340911903
  additional property: OTSTimestamp
    type: PropertyValue
    value: 2026-07-21T23:41:40Z
  additional property: OTSVerifyInstructions
    type: PropertyValue
    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
    type: DigitalDocument
    encoding format: application/vnd.opentimestamps.ots
    description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8a7d3184c2e2860ef4e3d565462ea2506134c1b79e3ca2ff8e0e80836c8b75c1. Chain 2 (Bitcoin): anchored in block 959076 (2026-07-21T23:41:40Z), 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/KRA340911903.
    date published: 2026-07-21T23:41:40Z
  audio: Separation Formula
    type: AudioObject
    additional property: Tempo (BPM)
      type: PropertyValue
      value: 129.965
    additional property: Musical Key
      type: PropertyValue
      value: 9
    additional property: Mode (Major/Minor)
      type: PropertyValue
      value: 1
    additional property: Time Signature
      type: PropertyValue
      value: 4
    additional property: Danceability
      type: PropertyValue
      value: 0.672
    additional property: Energy
      type: PropertyValue
      value: 0.968
    additional property: Speechiness
      type: PropertyValue
      value: 0.037
    additional property: Acousticness
      type: PropertyValue
      value: 0.086
    additional property: Instrumentalness
      type: PropertyValue
      value: 0.001
    additional property: Liveness
      type: PropertyValue
      value: 0.83
    additional property: Valence (Positivity)
      type: PropertyValue
      value: 0.844
    additional property: Loudness (dB)
      type: PropertyValue
      value: -7.293
    additional property: Key Name
      type: PropertyValue
      value: A
    additional property: Mode Name
      type: PropertyValue
      value: Major

It's R.ef
type: MusicAlbum
date published: 2012-09-25

왜이래
type: MusicAlbum
date published: 2013-09-10

Love is difficult - Remix
type: MusicRecording
duration: PT3M55S
duration ms: 235813
explicit: false
by artist: R.ef
in album: DJ Chully's Mix Mac 2005
  type: MusicAlbum
  date published: 2014-03-01
isrc code: KRY661430599
additional property: CopyrightID
additional property: CopyrightStatus
  type: PropertyValue
  value: registered
additional property: CopyrightRegisteredAt
  type: PropertyValue
  value: 2026-07-31T07:13:06+00:00
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0xdf62314c97d5a5096f90a3a026e8c1564eba4b08e1cf2e6509b4dabe1f6967d9
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 960368
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/960368
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/KRY661430599
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-07-31T08:26:41Z
additional property: OTSVerifyInstructions
  type: PropertyValue
  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
  type: DigitalDocument
  encoding format: application/vnd.opentimestamps.ots
  description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xdf62314c97d5a5096f90a3a026e8c1564eba4b08e1cf2e6509b4dabe1f6967d9. Chain 2 (Bitcoin): anchored in block 960368 (2026-07-31T08:26:41Z), 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/KRY661430599.
  date published: 2026-07-31T08:26:41Z
audio: Love is difficult - Remix
  type: AudioObject
  additional property: Tempo (BPM)
    type: PropertyValue
    value: 145.201
  additional property: Musical Key
    type: PropertyValue
    value: 4
  additional property: Mode (Major/Minor)
    type: PropertyValue
    value: 0
  additional property: Time Signature
    type: PropertyValue
    value: 5
  additional property: Danceability
    type: PropertyValue
    value: 0.713
  additional property: Energy
    type: PropertyValue
    value: 0.992
  additional property: Speechiness
    type: PropertyValue
    value: 0.049
  additional property: Acousticness
    type: PropertyValue
    value: 0.007
  additional property: Instrumentalness
    type: PropertyValue
    value: 0.41
  additional property: Liveness
    type: PropertyValue
    value: 0.289
  additional property: Valence (Positivity)
    type: PropertyValue
    value: 0.942
  additional property: Loudness (dB)
    type: PropertyValue
    value: -7.165
  additional property: Key Name
    type: PropertyValue
    value: E
  additional property: Mode Name
    type: PropertyValue
    value: Minor