I was there last night, and I'll be there again tonight. I don't know if there are tickets available for tonight's show or for tomorrow's matinee (which I cannot attend due to a previous commitment) -- but you should find out, and go to whichever show you can.
In years to come, Emperor Norton's Stationary Marching Band and the Madcap Rumpus Society are certain to become big names, at least in the Massachusetts vicinity, if not the nation or world. You'll be able to say you were there at the start. And you'll want to be able to say that.
If you're going tonight and see this by 5 or so -- ping me. I'd like to meet for diner and/or drinks before the show. A nightcap or midnight snack afterward would also be a win, so let me know if you're interested!
Edited To Add: Box office opens at 6pm or so. Word is there are less then 50 tickets remaining as of 4pm. It's 5:15pm now. Be there or be regretful!