To the request of a friend I will post this, apparently this has to be "Cass's law of animation", but it is worthwhile talking about it.
We were discussing teaching to animate to a beat and I asked the simple question "you will be using the bouncing ball?"
"no" apparently the "bouncing ball, tired of teaching this"
"oh" and " I still persisted "but, without the ball the students will not know how to judge the timing and spacing of the music?"
I then thought about it and then said "why can't you have the bouncing ball of to the side? still it will remind the students the timing and spacing of the scene"
Using Ollie's beautifully drawn cat as an example
The problem is since the removal of the "Dope sheet" to check what you want out of the animation, you have to refer back to "life action reference" or "thumbnails", what if you could see the animation timing and spacing off to the side as your bouncing ball? Emphasising certain parts of your scene or getting the beat right before you jump and the principles of animation is all ways with you with the faithful bouncing ball.