MC18 added a new way to save and play playlists and Play Doctor playcharts. You will find it by opening Playing Now. Look for the numbered buttons on the right and half way down.
If you wish to generate a Play Doctor Play Chart, you will also need to stop playback of the current list.
Populating buttons and using them to play works like the buttons on a car radio. You press and hold to save. You press to play.
Buttons 1 through 8 appear on the Car Radio dashboard. Right click on the buttons to change the number visible.
Press and Hold to save the currently playing playlist.
If you're playing an ordinary playlist, it will save it. You have an option to save as an ordinary playlist or as a play chart (Play Doctor).
This feature is intended to make it easy for casual users to start playback.
MC23 added the ability to auto-fill the buttons.