Hello, couldn’t info on this.
Do you need level/ world selected behind main menu when you use main menu widget on top of it anyways?
If no, is there any example on internet on how to add background melody using blueprints?
Yes, you need at least an empty level as the first level of the game where you create your main menu widget. But it’s not necessary for sound, you can play it inside your menu widget as well if you like.