Duofel
type: MusicGroup
genre: brazilian jazz
description: Duofel is an acoustic guitar duo from Brazil. The duo, consisting of Fernando Melo and Luiz Bueno, was founded in 1977 and has released several recordings. They have collaborated with the tabla play
popularity: 20
followers: 3080
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
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additional property: OTSBitcoinBlock
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additional property: OTSBitcoinBlockVerifyURL
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additional property: OTSProofURL
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  value: https://artists.proofprofile.net/proofs/artist/21d005cc-3685-495b-b6f9-aef5b71da571.ots
additional property: OTSRecordURL
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additional property: OTSVerificationAPI
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additional property: OTSTimestamp
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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
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  encoding format: application/vnd.opentimestamps.ots
  description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe2fe400039316a7cc8e12b41950500bb5aa6bcb4d5801f67d6dad18a3e3998c8. Chain 2 (Bitcoin): anchored in block 953626 (2026-06-14T11:41:45Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/21d005cc-3685-495b-b6f9-aef5b71da571.json and https://artists.proofprofile.net/proofs/artist/21d005cc-3685-495b-b6f9-aef5b71da571.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-14T11:41:45Z
album: As Cores do Brasil
  type: MusicAlbum
  date published: 1990-05-10
album: Duofel
  type: MusicAlbum
  date published: 1993
album: Duofel
  type: MusicAlbum
  date published: 1993-09-10
album: Espelho das Águas
  type: MusicAlbum
  date published: 1994-01-04
album: Espelho das Águas
  type: MusicAlbum
  date published: 1994-06-10
album: Kids of Brazil
  type: MusicAlbum
  date published: 1996-05-04
album: Atenciosamente, Duofel
  type: MusicAlbum
  date published: 1999
album: Duofel 20
  type: MusicAlbum
  date published: 2000-10-09
album: Duofel Experimenta Playing at Home
  type: MusicAlbum
  date published: 2007-02-04
album: Experimenta Lounge Eletrônico
  type: MusicAlbum
  date published: 2007-03-04
album: Olho de Boi
  type: MusicAlbum
  date published: 2008-07-06
album: Duofel Plays The Beatles
  type: MusicAlbum
  date published: 2009
album: Duofel Plays the Beatles
  type: MusicAlbum
  date published: 2009-05-09
album: Duofel Pulsando MPB
  type: MusicAlbum
  date published: 2010-06-12
album: Duofel Pulsando MPB
  type: MusicAlbum
  date published: 2013-06-20
album: Precioso
  type: MusicAlbum
  date published: 2013-09-16
album: Atenciosamente, Duofel
  type: MusicAlbum
  date published: 2013-09-16
album: Playing the Game
  type: MusicAlbum
  date published: 2014-03-05
album: Instrumental no CCBB
  type: MusicAlbum
  date published: 2016-05-12
album: Duo+Dois
  type: MusicAlbum
  date published: 2019-03-15
album: Duo+Dois
  type: MusicAlbum
  date published: 2019-03-25
album: Duo+Dois
  type: MusicAlbum
  date published: 2019-03-25
track: Todo Esse Tempo No. 1
  type: MusicRecording
  duration: PT1M51S
  duration ms: 111946
  explicit: false
  by artist: Itamar Assumpção
  by artist: Duofel
  in album: Pretobrás II - Maldito Vírgula
    type: MusicAlbum
    date published: 2010-09-11
  genre: brazilian-indie
  genre: mpb
  genre: samba
  genre: samba-paulista
  genre: bossa-nova
  genre: velha-guarda
  isrc code: BRSC41000087
  additional property: CopyrightID
  additional property: CopyrightStatus
    type: PropertyValue
    value: registered
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    type: PropertyValue
    value: 2026-07-29T10:36:36+00:00
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    value: https://explorer.copyrightchains.com/tx/0x37d20f1dfbf2771dbd302dbe415c57815895748454add2954b781126dcd0418f
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    type: PropertyValue
    value: https://blockstream.info/api/block-height/960095
  additional property: OTSVerificationAPI
    type: PropertyValue
    value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/BRSC41000087
  additional property: OTSTimestamp
    type: PropertyValue
    value: 2026-07-29T11:07:37Z
  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 0x37d20f1dfbf2771dbd302dbe415c57815895748454add2954b781126dcd0418f. Chain 2 (Bitcoin): anchored in block 960095 (2026-07-29T11:07:37Z), 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/BRSC41000087.
    date published: 2026-07-29T11:07:37Z
  audio: Todo Esse Tempo No. 1
    type: AudioObject
    additional property: Tempo (BPM)
      type: PropertyValue
      value: 113.859
    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
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    additional property: Energy
      type: PropertyValue
      value: 0.433
    additional property: Speechiness
      type: PropertyValue
      value: 0.052
    additional property: Acousticness
      type: PropertyValue
      value: 0.778
    additional property: Instrumentalness
      type: PropertyValue
      value: 0.024
    additional property: Liveness
      type: PropertyValue
      value: 0.134
    additional property: Valence (Positivity)
      type: PropertyValue
      value: 0.783
    additional property: Loudness (dB)
      type: PropertyValue
      value: -17.047
    additional property: Key Name
      type: PropertyValue
      value: E
    additional property: Mode Name
      type: PropertyValue
      value: Minor
track: A Barca (La Barca)
  type: MusicRecording
  duration: PT3M53S
  duration ms: 233080
  explicit: false
  by artist: MPB4
  by artist: Duofel
  in album: Contigo Aprendi
  genre: mpb
  genre: samba
  genre: bossa-nova
  isrc code: BRPUI1100807
  additional property: CopyrightID
  additional property: CopyrightStatus
  additional property: CopyrightRegisteredAt
  additional property: CopyrightChainExplorerURL
  additional property: OTSHash
  additional property: OTSBitcoinBlock
  additional property: OTSBitcoinBlockVerifyURL
  additional property: OTSVerificationAPI
  additional property: OTSTimestamp
  additional property: OTSVerifyInstructions
  subject of: OpenTimestamps Proof of Existence
  audio: A Barca (La Barca)
track: Sabor Em Mim (Sabor a Mi)

Duofel
type: MusicGroup

Contigo Aprendi
type: MusicAlbum
date published: 2012-06-12

CopyrightID
type: PropertyValue

CopyrightStatus
type: PropertyValue
value: registered

CopyrightRegisteredAt
type: PropertyValue
value: 2026-06-20T08:33:27+00:00

CopyrightChainExplorerURL
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value: https://explorer.copyrightchains.com/tx/0xa41815293cee44bd830df829262fcb22c76e6366f31e1705a7802df3ab6833fa

OTSHash
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OTSBitcoinBlock
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value: 956302

OTSBitcoinBlockVerifyURL
type: PropertyValue
value: https://blockstream.info/api/block-height/956302

OTSVerificationAPI
type: PropertyValue
value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/BRPUI1100807

OTSTimestamp
type: PropertyValue
value: 2026-07-02T03:30:09Z

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

OpenTimestamps Proof of Existence
type: DigitalDocument
encoding format: application/vnd.opentimestamps.ots
description: Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa41815293cee44bd830df829262fcb22c76e6366f31e1705a7802df3ab6833fa. 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/BRPUI1100807.
date published: 2026-07-02T03:30:09Z

A Barca (La Barca)
type: AudioObject
additional property: Tempo (BPM)
  type: PropertyValue
  value: 117.874
additional property: Musical Key
  type: PropertyValue
  value: 2
additional property: Mode (Major/Minor)
  type: PropertyValue
  value: 0
additional property: Time Signature
  type: PropertyValue
  value: 5
additional property: Danceability
  type: PropertyValue
  value: 0.684
additional property: Energy
  type: PropertyValue
  value: 0.409
additional property: Speechiness
  type: PropertyValue
  value: 0.036
additional property: Acousticness
  type: PropertyValue
  value: 0.865
additional property: Instrumentalness
  type: PropertyValue
  value: 0.001
additional property: Liveness
  type: PropertyValue
  value: 0.089
additional property: Valence (Positivity)
  type: PropertyValue
  value: 0.2
additional property: Loudness (dB)
  type: PropertyValue
  value: -14.226
additional property: Key Name
  type: PropertyValue
  value: D
additional property: Mode Name
  type: PropertyValue
  value: Minor

Sabor Em Mim (Sabor a Mi)
type: MusicRecording
duration: PT3M23S
duration ms: 203346
explicit: false
by artist: MPB4
by artist: Duofel
in album: Contigo Aprendi
  type: MusicAlbum
  date published: 2012-06-12
genre: mpb
genre: samba
genre: bossa-nova
isrc code: BRPUI1100922
additional property: CopyrightID
additional property: CopyrightStatus
  type: PropertyValue
  value: registered
additional property: CopyrightRegisteredAt
  type: PropertyValue
  value: 2026-07-31T11:22:34+00:00
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0x0e5d10790894cb60627e509514b6c017e13c37dfce7dcdf03f10bec2456c41e8
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 960397
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/960397
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/BRPUI1100922
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-07-31T12:24:41Z
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 0x0e5d10790894cb60627e509514b6c017e13c37dfce7dcdf03f10bec2456c41e8. Chain 2 (Bitcoin): anchored in block 960397 (2026-07-31T12:24:41Z), 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/BRPUI1100922.
  date published: 2026-07-31T12:24:41Z
audio: Sabor Em Mim (Sabor a Mi)
  type: AudioObject
  additional property: Tempo (BPM)
    type: PropertyValue
    value: 121.403
  additional property: Musical Key
    type: PropertyValue
    value: 0
  additional property: Mode (Major/Minor)
    type: PropertyValue
    value: 1
  additional property: Time Signature
    type: PropertyValue
    value: 5
  additional property: Danceability
    type: PropertyValue
    value: 0.734
  additional property: Energy
    type: PropertyValue
    value: 0.449
  additional property: Speechiness
    type: PropertyValue
    value: 0.04
  additional property: Acousticness
    type: PropertyValue
    value: 0.922
  additional property: Instrumentalness
    type: PropertyValue
    value: 0.001
  additional property: Liveness
    type: PropertyValue
    value: 0.123
  additional property: Valence (Positivity)
    type: PropertyValue
    value: 0.353
  additional property: Loudness (dB)
    type: PropertyValue
    value: -13.222
  additional property: Key Name
    type: PropertyValue
    value: C
  additional property: Mode Name
    type: PropertyValue
    value: Major