Once upon a time, you were guaranteed flawlessness from a Pixar production, aside from the odd “Cars” flick here and there. The studio has, however, become something of a sequel mill over the past decade, boasting only a few masterworks since the halcyon days of “Ratatouille,” “WALL-E” and “Up”; the five years since they released what was arguably their greatest work, “Inside Out,” stands out as something of a creative no man’s land. “Soul,” you’ll be glad to know, is a mesmerizing return to form; it’s a veritable smorgasbord for the senses, vividly recapturing the joys hidden in life’s most banal moments, just as excited about a grease-soaked slice of pizza as it is a leaf floating in the autumn breeze. My oh my, what a nourishing tonic for the current moment.