### install blackhole

using Homebrew

```
brew install --cask blackhole-2ch
```

### mess around with MacOS audio device settings

applies to intel macs as well

https://www.avtouchbar.com/blackhole-m1-macs/

### play the music, using `ffmpeg` to record it

i created this shell script: `recordff.sh` using info from the [forums](https://github.com/ExistentialAudio/BlackHole/discussions/8#discussioncomment-1863071)

```lang-sh
#!/bin/zsh

./basic ffarpeggio.bas &

export FFMPEG_FMT_SYSTEM_AUDIO=avfoundation
export FFMPEG_INPUT_DEVICE_SYSTEM_AUDIO=":0"

echo "Recording system audio."

ffmpeg\
  -nostdin\
  -f ${FFMPEG_FMT_SYSTEM_AUDIO}\
  -i ${FFMPEG_INPUT_DEVICE_SYSTEM_AUDIO}\
  system_audio.wav
```

Note, the program `ffarpeggio.bas` is [here](https://codegolf.stackexchange.com/a/275614/15940), and the `basic` executable is RHN's [Chipmunk Basic](http://www.nicholson.com/rhn/basic/)