Grateful Dead Sticker, Northampton

My brother and I got to the Iron Horse Music Hall very early for The Nields concert on June 17th. So early that we had time to get a drink at a nearby bar. I forget the name of the place, but I loved it. I had a Guinness, and the bartender poured it correctly, taking his time, and even putting the shamrock in the foam. And on the wall was this Grateful Dead sticker that I had never seen before. Anyone know about this one? (By the way, even after a leisurely drink, we were still first in line for the concert, and so got the table we wanted.)