Select every object on the stage generically

I’m trying to find a generic way to select everything on the stage, because when I leave a frame, I want everything to fade out. But the user will be leaving multiple frames, so I would like to do it without specifying various objects depending on what frame they’re on. I realize there are a lot of ways to “skin this cat”, and I will fall back on something else if this isn’t possible.

When I try this, I get an error, “undefined *”.

stage.*.alpha = 0;

Any ideas?