The Media Key Binder lets you assign a key combination to play/pause whichever desktop program is running. (Spotify, Windows Media Player, iTunes, etc...)
This is useful if you switch computers or laptops (probably at work) and keep forgetting where the play/pause key is on that machine.
Just click the lock.
Select your modifier keys (Ctrl, Alt, Shift)
And push your key.
Your key is set. Happy Listening!