This Sunday night on “The Lost Chord,” we focus on “The Virgin Spring.” No, not the Bergman film, in which Max von Sydow exacts terrible vengeance on those who… well, nevermind. See the movie.

Anyway, the show’s not about that. The spring in the film is a body of water, a symbol of rebirth and renewal, but we’re using “spring” in the purely seasonal sense, as we enjoy an hour of vernal expressions by Swedish composers.

We’ll hear the “Pastoral Suite,” by Gunnar de Frumerie, and two works by Wilhelm Peterson-Berger: first, one of the books from his collection “Flowers of Frösö;” then the “Earina Suite.” “Earina,” derived from the Greek “earinos,” meaning “spring-like,” according to the composer, conjures a world of “cult deeds and magic rites… belonging to some undefined natural religion.” Appropriate music, then, for Walpurgis Night.

The long winter dissolves in the lengthening days of “The Virgin Spring,” this Sunday night at 10 EDT, on WWFM – The Classical Network and at wwfm.org.