Part of the fun of being a newbie turner is discovering how to do things that are common knowledge for more experienced turners. Case in point - cutting a ring free from the surrounding turning. Using a 1/2" skew, I undercut the disk on both sides with the lathe on. I turned the lathe off and manually turned the piece to make the final through cut. Then I cleaned out the remaining stubble on the "background" so the free ring could move out of the way enough to turn that area smooth. Set the lathe to its lowest speed and turned it on. A little work with a small spindle gouge and then tapped the ring loose.
It started dancing. Change the speed and the dance changed. So I did three more, changing the side slopes and lengths. Interesting.