Piano Sonata No. 2 in B-Flat Minor, Op. 36: II. Non allegro - Lento (Version 1931)
type: MusicRecording
duration: PT5M49S
duration ms: 349033
explicit: false
by artist: Sergei Rachmaninoff
by artist: Martin Klett
in album: Guastavino & Rachmaninoff
  type: MusicAlbum
  date published: 2018-03-16
genre: classical
genre: classical-piano
isrc code: DEAQ71739716
additional property: CopyrightID
additional property: CopyrightStatus
  type: PropertyValue
  value: registered
additional property: CopyrightRegisteredAt
  type: PropertyValue
  value: 2026-08-01T00:12:05+00:00
additional property: CopyrightChainExplorerURL
  type: PropertyValue
  value: https://explorer.copyrightchains.com/tx/0xf8a09ab4f08fea9db54ecd0774086c79e419e3067209aa332f6a4707d61fbf23
additional property: OTSHash
additional property: OTSBitcoinBlock
  type: PropertyValue
  value: 960489
additional property: OTSBitcoinBlockVerifyURL
  type: PropertyValue
  value: https://blockstream.info/api/block-height/960489
additional property: OTSVerificationAPI
  type: PropertyValue
  value: https://artists.proofprofile.net/api/v1/bot/ots/verify/track/DEAQ71739716
additional property: OTSTimestamp
  type: PropertyValue
  value: 2026-08-01T00:40:43Z
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 0xf8a09ab4f08fea9db54ecd0774086c79e419e3067209aa332f6a4707d61fbf23. Chain 2 (Bitcoin): anchored in block 960489 (2026-08-01T00:40:43Z), 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/DEAQ71739716.
  date published: 2026-08-01T00:40:43Z
audio: Piano Sonata No. 2 in B-Flat Minor, Op. 36: II. Non allegro - Lento (Version 1931)
  type: AudioObject
  additional property: Tempo (BPM)
    type: PropertyValue
    value: 97.549
  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: 0.304
  additional property: Energy
    type: PropertyValue
    value: 0.06
  additional property: Speechiness
    type: PropertyValue
    value: 0.047
  additional property: Acousticness
    type: PropertyValue
    value: 0.993
  additional property: Instrumentalness
    type: PropertyValue
    value: 0.895
  additional property: Liveness
    type: PropertyValue
    value: 0.076
  additional property: Valence (Positivity)
    type: PropertyValue
    value: 0.041
  additional property: Loudness (dB)
    type: PropertyValue
    value: -29.021
  additional property: Key Name
    type: PropertyValue
    value: E
  additional property: Mode Name
    type: PropertyValue
    value: Minor