len.czu
type: MusicGroup
popularity: 10
followers: 174
additional property: CopyrightID
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0x9b8fe2b47a74e4bed955d36ece58c348fa2a1e671e68eaa8699acc7a25c9942d
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 954065
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/954065
additional property: OTSProofURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/52e2178d-a160-49b9-b16b-b0556b5ee1c3.ots
additional property: OTSRecordURL
  type: PropertyValue
  value: https://artists.proofprofile.net/proofs/artist/52e2178d-a160-49b9-b16b-b0556b5ee1c3.json
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/artist/52e2178d-a160-49b9-b16b-b0556b5ee1c3
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-06-17T08:10:43Z
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 0x9b8fe2b47a74e4bed955d36ece58c348fa2a1e671e68eaa8699acc7a25c9942d. 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/52e2178d-a160-49b9-b16b-b0556b5ee1c3.json and https://artists.proofprofile.net/proofs/artist/52e2178d-a160-49b9-b16b-b0556b5ee1c3.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
  date published: 2026-06-17T08:10:43Z
album: Polska Zima
  type: MusicAlbum
  date published: 2025-02-11
  track: Polska Zima
    type: MusicRecording
    duration: PT2M32S
    duration ms: 152000
    explicit: false
    by artist: len.czu
    in album: Polska Zima
      type: MusicAlbum
      date published: 2025-02-11
    isrc code: PLI362069050
    additional property: CopyrightID
    additional property: CopyrightStatus
      type: PropertyValue
      value: registered
    additional property: CopyrightRegisteredAt
      type: PropertyValue
      value: 2026-07-04T07:07:26+00:00
    additional property: CopyrightChainExplorerURL
      type: PropertyValue
      value: https://explorer.copyrightchains.com/tx/0x1d3103580acd64618efbc960ff512b7645e4c392797232765b36d33d9cc37c51
    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/PLI362069050
    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 0x1d3103580acd64618efbc960ff512b7645e4c392797232765b36d33d9cc37c51. 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/PLI362069050.
      date published: 2026-07-04T10:04:33Z
    audio: Polska Zima
      type: AudioObject
      additional property: Tempo (BPM)
        type: PropertyValue
        value: 119.982
      additional property: Musical Key
        type: PropertyValue
        value: 10
      additional property: Mode (Major/Minor)
        type: PropertyValue
        value: 0
      additional property: Time Signature
        type: PropertyValue
        value: 4
      additional property: Danceability
        type: PropertyValue
        value: 0.699
      additional property: Energy
        type: PropertyValue
        value: 0.346
      additional property: Speechiness
        type: PropertyValue
        value: 0.162
      additional property: Acousticness
        type: PropertyValue
        value: 0.511
      additional property: Instrumentalness
        type: PropertyValue
        value: 0.215
      additional property: Liveness
        type: PropertyValue
        value: 0.076
      additional property: Valence (Positivity)
        type: PropertyValue
        value: 0.076
      additional property: Loudness (dB)
        type: PropertyValue
        value: -18.297
      additional property: Key Name
        type: PropertyValue
        value: Bb
      additional property: Mode Name
        type: PropertyValue
        value: Minor
album: Vincent
  type: MusicAlbum
  date published: 2025-04-01
album: Kraków EP
  type: MusicAlbum
  date published: 2025-04-22
album: Wino
  type: MusicAlbum
  date published: 2025-06-25
album: All About The Vibes
  type: MusicAlbum
  date published: 2025-07-17
album: Niedopowiedzenia
  type: MusicAlbum
  date published: 2025-09-28
  track: Niedopowiedzenia
    type: MusicRecording
    duration: PT2M2S
    duration ms: 122146
    explicit: false
    by artist: len.czu
    in album: Niedopowiedzenia
      type: MusicAlbum
      date published: 2025-09-28
    isrc code: PLI369858130
    additional property: CopyrightID
    additional property: CopyrightStatus
      type: PropertyValue
      value: registered
    additional property: CopyrightRegisteredAt
      type: PropertyValue
      value: 2026-07-05T11:58:55+00:00
    additional property: CopyrightChainExplorerURL
      type: PropertyValue
      value: https://explorer.copyrightchains.com/tx/0x5147263572e022cf823446f6cd83fb09c08e6d1a5f1046a05bfd91315924d6cc
    additional property: OTSHash
    additional property: OTSBitcoinBlock
      type: PropertyValue
      value: 956822
    additional property: OTSBitcoinBlockVerifyURL
      type: PropertyValue
      value: https://blockstream.info/api/block-height/956822
    additional property: OTSVerificationAPI
      type: PropertyValue
      value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/PLI369858130
    additional property: OTSTimestamp
      type: PropertyValue
      value: 2026-07-05T18:48:28Z
    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 0x5147263572e022cf823446f6cd83fb09c08e6d1a5f1046a05bfd91315924d6cc. Chain 2 (Bitcoin): anchored in block 956822 (2026-07-05T18:48:28Z), 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/PLI369858130.
      date published: 2026-07-05T18:48:28Z
    audio: Niedopowiedzenia
      type: AudioObject
      additional property: Tempo (BPM)
        type: PropertyValue
        value: 102.986
      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: 0.769
      additional property: Energy
        type: PropertyValue
        value: 0.41
      additional property: Speechiness
        type: PropertyValue
        value: 0.098
      additional property: Acousticness
        type: PropertyValue
        value: 0.079
      additional property: Instrumentalness
      additional property: Liveness
      additional property: Valence (Positivity)
      additional property: Loudness (dB)
      additional property: Key Name
      additional property: Mode Name

Instrumentalness
type: PropertyValue
value: 0.025

Liveness
type: PropertyValue
value: 0.055

Valence (Positivity)
type: PropertyValue
value: 0.136

Loudness (dB)
type: PropertyValue
value: -13.878

Key Name
type: PropertyValue
value: A

Mode Name
type: PropertyValue
value: Minor