I've noticed that in one of the recent updates to the Spotify Windows desktop app, the ALT+Space context menu has been disabled. I can't think of any scenario where that would have been a good idea? I regularly minimise windows with the shortcut chord 'ALT+Space, N' and it's very frustrating not being able to do this with Spotify any longer.
This should work again in the newest version. Alt + space brings up the menu again. 😉