Etude for Piano: Guero (1970)

Recording by Helmut Lachenmann.

Recording identifiers

ISRC
SEWDL0724804
Release date of the album this recording appears on
2009-11-17
CopyrightID (CopyrightChains transaction hash)
0xbb2e3218161ef4e0e5cc59e40b0d2b0a3438a29c46ca932ca6eb13244fce5798
Copyright registration time
2026-07-30T15:45:17+00:00

OpenTimestamps proof evidence

Bitcoin-attested timestamp
2026-07-30T16:01:17Z
Bitcoin block
960276
Canonical record hash
sha256:2ba0f035d0164b4b74fd02c5430c55fd87d4d0497d9c2cefa07227836a530dee

What this proof establishes

This recording was released in 2009, before generative AI. ProofProfile's catalogue derives from the pre-2022 AcousticBrainz and MusicBrainz source corpus, and ISRC is the stable recording-level bridge from that source corpus to the authoritative cc-db-prod track record.

CopyrightChains and Bitcoin OpenTimestamps make the exact committed record independently verifiable today. The cryptographic proof does not by itself establish authorship or ownership of the underlying recording.

Read the complete pre-generative-AI provenance and verification method.