It's a artifact for praying rain.
In the future, there is no rain in the world. The only things we have are the extreme hotness of day and extreme coldness of night.
People desire the memory of rain. This box can convert sunshine to the memory of rain. When we put this box under sunshine, the drops on the cover can show themselves by changing color. When putting it to shady area, it can play “Singin’ in the Rain” (a song) for helping prayers enjoy the beauty of rain.
At the beginning, I use shower curtain to make speak. The volume of sound it triggers is too weak.
Then I change it to wax paper. It's still weak, but a bit stronger.
So for the final piece, I replace it with a manufactured speaker attached with magnets for stronger volume. The video below is showing the working prototype.