Home of the Tango Society of Boston, Dance Union has been open since June 2008. Owner Vicki Magaletta, who is also the president of the Tango Society, works diligently to bring a rotating coral of world-class instructors from across the globe to her Union Square establishment. Offering group and private lessons in tango, salsa and blues, Dance Union is open late into the night, its brightly lit dance floor visible from Bow Street a story below.