This weekend – hell, this entire last week – might well be one of the most overwhelming, surreal, stressful, harrowing, [insert adjective to describe any one of the hundreds of emotions experienced while following the manhunt in Watertown on Friday in real time] roller coaster rides that the people of Boston have experienced in a very long time. Maybe ever. Now, it’s time for the the city to rebuild, recoup, and figure out how to process all those aforesaid emotions. Getting our collective groove back with of one of this town’s long-running music institutions seems as a good a place as any to start.