You can undo most of what you did yo something you draw or paint with a digital device so experimenting with new creating ideas on work you are doing has no cost because you can always go back to a previous version. It might be fun to have a similar option when you are drawing in the real analog world and not on a digital device.
A transparent “paper” that behaves like real paper, so it reacts to your drawing and painting utensils (pencils, pastels, etc.) in a similar way to real paper. You can then have new layers of this “paper” added to your work and experiment. If you don’t like the result, just through away the top layer(s) of this “paper.”
When you buy music and listen to it, again and again, you will always hear the same one, without any variation. Live music at concerts is always a little different from the recorded version and also from live performance to live performance.
Have different versions recorded for each piece of music (in studio, live performances, both.) When you buy the music (for download or streaming) you get access to all the versions. You can choose which version to listen to at any given time, or let the software decide randomly or based on your previous behavior. A new digital format can also be created where you can break down the elements of the music so that the performer can record alternative elements for individual parts and they can be dynamically exchanged or added when you play the music.