Entirely Self Working
Imagine this: You ask everyone in the audience to write down their favorite song (or anything) on a slip of paper and drop it into the box. It never goes out of sight and (truly) nobody touches it. You invite a spectator to approach the box and open it, then reach inside and remove any slip at random.
In the act of opening the box, the spectator unknowingly switches all of the audience's papers for an entirely different batch of slips you prepared in advance. You can later access the REAL slips as well, if desired.
Instant Setup. No Reset.
One box. Infinite possibilities. It's as light as air, and it can be decorated or repurposed in any way you like. You (the performer) don't even touch the box.
Packs completely flat for easy travel, requiring minimal space. No electronics. In fact, the method is most closely related to origami.