How do you make a quick change dress?

Here's one way I know how.

Get two dresses. One should be shorter length, have a looser fitting bodice (blousy?), be lower waisted, and have sleeves or go up to the shoulders. The other should be very lightweight, have a higher waist (empire?) and either have straps or be strapless.

Alter the short dress by putting snaps or velcro on the shoulder seams (as well as the sleeves on the top if you have sleeves). Put that dress on first, with the bodice undone and hanging down.

Put on the longer dress, then carefully roll or pleat the skirt fabric until you can pack it into the bodice of the first dress. Pull up that bodice and close snaps or velcro. The skirt fabric of the second dress should be so sheer that it will fit without making you look too bulky.

When you're ready, you can do this quick change within a tube of fabric, behind a quick backdrop, or if you're a dancer, by releasing the shoulder catches and twirling

Try it out!