Just as you can see the entire bar highlight when you play, it would be helpful to see it after it was recorded and once it is looping as well.
Like a player piano, when the keys are depressed when it's playing automatically.
Creating an ability to turn this on or off will allow you to watch the performance as well as hear it. It will also be helpful as an educational tool to learn how other artists played a session or loop set and see the exact notes as it was played.