static File nonVoiceMegaMix() {
  File file = javaxDataDir("Generated Audio/non-voice-mega-mix.wav");
  if (!file.exists()) {
    new AudioInputStreamsCollector c;
    // TODO: files without markers
    for (File f : allRecordingsWithoutMarkers()) {
      if (!f.getName().startsWith("[")) continue;
      print(f.getName());
      addClipToAudioCollector(spectro_clipFromFile(f), c);
    }
    c.writeToWAV(file);
  }
  ret file;
}

Began life as a copy of #1019221