Ah. We were trying to get rid of it.
If you press Alt+3 you get the piano roll (but it peeks up under the track view, so you need to drag the splitter bar all the way up)
Now, when you press Alt+1, you get track view. D also seems to work for some reason.
The other views also work traditionally again (although the Alt+n numbers have changed).
So Alt+2 opens Console view, Alt+6 opens Staff view, etc.
But if I undock, strange things begin to happen.
If I press Alt+1, I get track view again. But none of the other Alt+n keys work anymore. I now need to press D!
I think screen sets are easier to use. But then I want to get rid of the Multidock so I can get some screen space back.