Actually, that landing between street level and turnstile level might be a good place for everybody to assemble. If you get off the train and go through the turnstiles, you see a flight of stairs and two escalators right in front of you. Up you go to the landing - I think that'd be a good place to meet up, then we figure out what to do and head on up to the street from there. If you take the bus into one of the tunnels adjacent to the subway platforms, just look around for the Dunkin' Donuts - the aforementioned stairs/escalators are right next to it. How's that sound? As for the concert, depends on how late in the afternoon it is. Next train after the 6:35 isn't until 11:15.