AI-Assisted Reverse Engineering of a Piano Format Raises Legal Questions

Summary

A Hacker News user describes using the AI systems Astra and Fable to create a preferred version of Erik Satie’s “Gymnopédie No. 1” for a PianoDisc self-playing piano. After comparing an open-source file and a purchased PianoDisc MP3, Fable reportedly identified a 2,004.5 Hz square wave on the right channel that carries MIDI data, while the left channel contains accompanying audio. The system also analyzed pedal lift, melody, chord balance, rubato and sustain, then generated Python code for both an encoder and a decoder. Its explanation said PianoDisc uses decoy notes as obfuscation: the decoder removes them, while the encoder adds them so generated files remain compatible with the format. The author asks whether publishing either tool would be permissible. Hacker News commenters disagree about whether the mechanism could qualify as an effective technical measure under the US Digital Millennium Copyright Act, while others point to the service terms, which prohibit interfering with or circumventing security features. Several commenters stress that the answer depends on jurisdiction, licensing terms and the exact implementation, and advise consulting a lawyer rather than treating forum comments as legal advice. The author says they may contact PianoDisc and keep the repository private if the company objects. The discussion also notes that AI-generated code does not remove the underlying legal uncertainty.