I think I got a bit on with this topic: The band played at Capital Center in Landover, MD on February 27th.
Now for me as a European I don't have perfect geography knowledge about everything in the USA and I always thought that Washington just borders on the state of Maryland, but was annexed from it at some point in the past.
However, the Capital Center was the home of the Washington bullets for decades - could it be that Jon greeted the audience with "Good evening Washington" because of that?
If so, the mystery should be solved