Steve Martin, who recently created the Broadway musical Bright Star, is a wildly successful banjo performer, has written books, and occasionally does comedy, guest-curated an exhibition of landscape paintings by Canadian artist Lawren Harris at Boston’s Museum of Fine Arts. According to Martin, this is a one-time thing, born out of his interest in the painter. Harris was one of Canada’s celebrated “Group of Seven,†but relatively unknown in the States, and part of Martin’s goal is to place his work in the context of modernism. Martin explains his goals quite nicely in an interview below. Tonight, Martin will appear at a public opening for the show, which runs until June 12.