Resembling more of a personal tribute than exhaustive biography, Pietro Marcello‘s Lucio Dalla documentary, “For Lucio,” takes its title as an invitation. A rambling eulogy that is just as often confusing as it is profound, Marcello’s wisp of a film (running less than 80 minutes) may be missing key context for those not already versed in the life and music of the politically-oriented Italian singer-songwriter.