About
Background Music is a macOS audio utility that automatically pauses your music player when another audio source starts playing, and resumes playback once that source stops. It currently supports iTunes, Spotify, VLC, VOX, Decibel, Hermes, Swinsian, and GPMDP, and adding support for other players is described as usually straightforward.
The app also provides a volume slider for each application running on your system, letting you boost quiet applications above their maximum volume. It can additionally record system audio: with Background Music running, you can select it as the input device in QuickTime Player, and combine it with a microphone by creating an aggregate device in Audio MIDI Setup.
The project requires macOS 10.13 or later and can be installed from a downloadable package or via Homebrew. The website notes that Background Music is still in alpha.
What's new
All release notesHomebrew cask background-music 0.5.0 (sha256 c7742b48ac2e9ea955fea66e5c13bb56be5f1487e0b12bad93820984bccb69ef).