If to you the name “Norman Rockwell” symbolizes all that is cornball, delusional and bogus about the American self-image, we cannot urge you enough to visit the Frist’s survey, which spans 56 years of work that picks at three perpetual sore spots in contemporary art: the taint of commercial motivation in creative expression; the debate whether illustration belongs on a lower plane than capital-A art; and the problem of accessibility — i.e., is art that is enjoyable on its face and scans immediately really art? Engage his character studies of barbershop quartets and skinny-dipping kids and Thanksgiving suppers in this spirit, and you might be surprised at the fights corny old irrelevant Norman Rockwell can inspire — along with shock, if you’ve never experienced the shot to the heart that is his 1963 work “The Problem We All Live With,” as starkly effective a rendering of the ugliness of racism as a 20th century visual artist produced. (The juxtaposition of the Rockwell show and the current 30 Americans exhibit of work by leading artists, all African-American, is something no strong-hearted viewer should pass up.) I submit that there’s far more tension, neurosis and complicating detail in Rockwell’s work than draws attention — and that he’s as indisputably a major artist as Steven Spielberg. Let the arguments begin.