Based on chripopper's script posted on the AHK forums, this AutoHotKey script (or the compiled executable) offers global hotkeys to control the Spotify Windows client.
Launching the controller will automatically launch Spotify too.
and (as of now) closing the controller closes Spotify as well.
This is just something I put together for my own use. Huge thanks to chripopper, wherever you are. :)
Download the executable right HERE if you don't want to fiddle with git.
Ctrl + Up - Play/Pause current song
Ctrl + Right - Play next song
Ctrl + Left - Play previous song
Ctrl + PageUp/PageDown - Volume Up/Down
Ctrl + Down - Show currently played song notification
Ctrl + Alt + Down - Open Spotify window
Ctrl + Alt + S - Toggle Shuffle Mode
Ctrl + Alt + Left/Right - Seek backward/forward