You know how holiday dinners can get politically tense these days? Joni Mitchell wrote about such divides and how they can calcify our feelings toward ourselves and one another on “Borderline,” from 1994’s Turbulent Indigo. “Every income, every age/Every fashion-plated rage/Every measure, every gauge/Creates a borderline,” she sang. During Songs of Freedom, a new evening-length concert anchored by the wonderful drummer Ulysses Owens, Jr., the great Theo Bleckmann revisits the song with timely passion. Watch him, and keep the thought in your pocket this time of the year.