on the schedule there are people listed as being part of the Base Ticket. They are all performing at the Grand Staircase (which looks to be the stairs at the Art Institute). They are all performing all three days but in a different order each day. Weird.
So $50 buys you performances by these artists at the Art Institute:
Madison McFerrin
Marisa Anderson
Haley Fohr
Daniel Bachman
Mary Lattimore
and the āopportunityā to purchase tickets for other shows that day at approx their normal cost if that artist was just coming through town, but they are playing a short set.
I put together a cart with the three day pass and the artists I wanted to see and it was $308.