On Mac OS X Lion (and up), Sandbox protects your computer from software that may accidentally harm your computer, by limiting what they can do. That's good, really. It enables us, Mac users, to worry less about security, since together with Gatekeeper (enabled by default from Mountain Lion), they ensure that most of the possible damage simply can't be done.
However - while Apple went to great lengths to ensure that all useful application functionality remain working, with little or no modification - some things just can't be done in a Sandbox. For example, routing of key events. This leads to a situation where you press a button to play music in a 3rd party app - say, Gear - but Quicktime Player gets launched out of nowhere, or iTunes starts playing simultanously. That's no good.
Fortunately, there is a solution: a magical preference pane that routes these keypresses to just where they belong.
Note: Magic Keys is not needed if you've purchased Gear from outside the App Store - it can handle these matters itself.
If you are an Alfred Powerpack user, you can use the following Alfred workflow to control Gear's playback.
If you aren't using Alfred, but you are a power user who is seeking for a way to control playback externally, you can find a simple documentation below.
Special thanks goes to fellow user Kadrach who created the workflow!