By default, Mac always starts iTunes when you press Play media key on the keyboard even when VLC, Spotify, KKBox or Songbird player opened.
This can be annoying. This patch, authored by Farhan Ahmad, can remove the default behavior. And allows you to control the only opened player correctly.
cd ~/Documents/ git clone https://github.com/thebitguru/play-button-itunes-patch.git cd play-button-itunes-patch chmod u+x * ./Patch.command
And restart iTunes
Now, the media keys should not work for iTunes.
Patch.command again to re-enable.