How can I add a universal keybinding for a program? I want to add a key binding that allows me to use it even when the application is not in the foreground. Specifically how would I add play/skip/previous key bindings to Spotify?

I'm not looking for the media key bindings. They can stay as is. I would like to add custom ones with keys of my choosing.
This can be answered by this other question. Basically, you're going to want to create an Automator action and assign it a global shortcut using the Keyboard preferences panel.

Edit: @bmike , the dupe you referenced didn't answer his question. The one I linked to does.