Removing header entirely (so that the menu is on top of the background)

Hi there! I'm using Rock Star pro - love the theme in general but - I want to do two things I can't quite figure out: 1 - I want to be able to remove the header entirely. As you can see, without a header image I've got the menu on top of a black background: http://musicmanwilson.com/ I would rather that background shift up and have the menu on TOP of it - everything else I love. The way the menu/title shrink, etc. I just want to have all of that on TOP of the background. More like this site: https://aarontrumm.com/ at least on first load - on that one, once you scroll, the menu has a black background, I'd like to keep it transparent so I can see the background. 2 - I would love to be able to give a page a different background... I don't mind CSS and coding - just having trouble digging around figuring out how to do this. Thanks a bunch!