a440 runs music through the systems that claim to identify, label, and pay for AI music, then publishes what actually holds up. Every result is a named test on a real file. The method and the corpus are public.
Coverage so far: 2 generators fully tested, Suno v6-mini and ElevenLabs Music v1/v2, across 122 public tests. 36 passed, 85 did not, 1 is not publicly testable. The ElevenLabs Music v2.5 battery is mid-run: 14 of 38 reads complete, same failure pattern so far.
Detection at a glance: the ElevenLabs watermark survives 30 of 38 battery attacks. ACRCloud, the strongest third-party detector tested, catches the same master after 30 of 38 attacks and attributes every catch to ElevenLabs correctly. The two fail on different attacks. Layered together, only 3 of the 38 beat both: pitch +6%, reverb, and the acoustic path. Vendor attribution is reliable only for ElevenLabs and Suno so far: ACRCloud labels music from other vendors as Suno.
The download carries a signed AI label. None of the 38 real-world attacks leave it intact.
The watermark survives format churn and trims. Tempo, pitch, reverb, noise, EnCodec, or the acoustic path and it is gone. All 38 v2 reads complete. The v2.5 battery is 14 of 38, same failures so far.