Westport Country Playhouse will present Isaac Mizrahi, “Project Runway: All Stars” judge and Broadway performer, in “Isaac Mizrahi: Live in Concert,” on Saturday, March 7, at 8 p.m. Mizrahi’s one-of-a-kind show brings together comedy, commentary, and an array of classic and soon-to-be classic songs from Stephen Sondheim to Blondie, from Comden and Green to Madonna. The actor, host, writer, designer, and producer will be accompanied by his six-piece jazz band.