When the Fairmount Indigo Corridor Collaborative brought its community "visioning" process to Mattapan last December, the forum was packed. The Collaborative's Community Action Group (CAG) gathered residents, urban planners, architects and developers around six work tables in the community room at the Mattapan Branch Library ; replete with maps, markers, clips, and questions to prompt the work ahead. The table-sized maps were drawn from the City of Boston's Fairmount Indigo Planning Initiative launched in February 2012 to take advantage of the MBTA's expansion of commuter rail service. The CAG's facilitators wanted to know what kind of "transit-oriented development" Mattapan residents envisioned along the Blue Hills/Cummings corridor. Biggest surprise was how many people there voiced a desire for a more robust nightlife in Mattapan. Turns out, there was no need to convince anyone that Mattapan would benefit from having a cultural arts ce...