Many rich nations use art, music and movies to project an image to the world, but few take it as seriously as South Korea - today’s uncontested champion of cultural soft power. In the last 20 years, the nation’s singers and actors have thumped to Asian and then worldwide superstardom - signaled in 2012 by the viral amusement “Gangnam Style” (the first song to hit a billion views on YouTube); strengthened by the stadium-filling concerts of BTS, Loona and other K-pop bands; and capped recently by the unprecedented best picture Oscar for Bong Joon Ho’s “Parasite.”