I’m hoping to replicate a book a created a long time ago using now-extinct software. This is a page with rhythms inside boxes like little flash cards.
I suppose it isn’t actually necessary to exactly replicate the boxes. My first guess is that I would somehow place a blue music box directly on top of a graphics box but there may be a more elegant solution.
You could do as you describe with music frames on top of graphics frames in Dorico, but I think this layout would be much easier with InDesign or Affinity.
With five flows in separate music and text frames: You could use graphic frames and import some fancy outline. I used text frames since they can have a border.