“Song of the sea” is a spectacular film that explores the Celtic myth of Selkies, a mystical being that can change form between human and seal, through a simply-told and heartwarming story about a brother and a sister. “Song,” a traditionally-animated film, is also a visual feat. And despite a few moments in which the visual eclipses the story “Song” is a successful continuation of animation storytelling. The film, by director Tomm