Editor’s Note: The September edition of Boston Calling Music Festival kicked off last night at City Hall Plaza, a folkish slate that featured Iceland’s folk-pop crew Of Monsters And Men, North Carolina’s Americana torchbearers The Avett Brothers, and Philadelphia-based, South African-born singer-songwriter Gregory Alan Isakov. Check out Barry Thompson’s live review of the night here, and scan Eddy Leiva’s photo gallery below.