Easiest way to automatically pause music when removing device from Dock?

I'd like the music on my Droid 4 to automatically pause when I pull the thing out of the dock, no matter what. I don't need it to auto-play again later, just go to pause and stay there. What's the easiest way to do this? I'm willing to buy an app if it makes this simple. I normally use the built-in music player, but again I'm willing to try something else if it would help. If it's relevant, I have the phone set to not go into the dock app for desktop use.