Music Decoy: a tiny Mac utility that stops Apple Music from launching

Pressing the Play key on a Mac keyboard is supposed to resume whatever you were listening to. In practice macOS frequently responds by opening the Apple Music app — a behaviour that has annoyed users for years. Music Decoy, a small free utility from the developer behind lowtechguys.com, takes a different approach: instead of fighting the system, it pretends to be the Music app itself.

A process that does nothing

As long as Music Decoy is running, the system Music app will not launch when the Play key is pressed by accident. According to its documentation, the app performs "absolutely no work" in the background. It works simply by existing as a running process, because it carries the same bundle identifier as Apple's player: com.apple.Music. The system therefore believes Music is already running and does not start it again.

That trick also means the utility has no Dock icon and no menu bar item. To quit it, users have to find the process in Activity Monitor and press the stop button, or run "killall 'Music Decoy'" in Terminal.

When macOS opens Music by itself

The behaviour is not random. It appears when the Play key is pressed while no other application is playing audio, when a Bluetooth headset connects and sends a play command, and when a phone call ends and the headset switches from call mode back to music mode.

The culprit is a daemon called rcd — the Remote Control Daemon — which handles media keys. When a play event occurs, rcd checks whether an app is currently playing audio. If one is, the command goes to that app; if not, rcd launches the system Music app. Disabling the daemon is possible, but it also removes the ability to control playback from the keyboard.

Redirecting Play to another player

Since version 1.1, Music Decoy can send the Play event to a different application instead. The configuration is a single Terminal command — for example "defaults write com.lowtechguys.MusicDecoy mediaAppPath /Applications/Spotify.app" — and it can be reverted with a matching "defaults delete" command.

The page also lists alternatives: unloading the rcd launch agent with launchctl disables the Play button entirely, while the open-source noTunes watches for launched apps and kills Music as soon as it appears, at the cost of a small amount of background CPU time. Music Decoy installs with a single Homebrew command, "brew install music-decoy".