Wilco dropped their coyly titled ninth album as a free-download surprise, but even more unexpected is just how loose it all sounds. The long-running band unwind with a warm set of shaggy, psych-tinged indie rock. It’s a bountiful feast for guitar lovers, from the pervasive growling distortion to Nels Cline’s prickly riffage. Jeff Tweedy taps a renewed drollness in the lyrics for “Random Name Generator” and especially “The Joke Explained,” while teasing a disheveled stoner edge on “Cold Slope” and the overdriven, falsetto-licked “Pickled Ginger.”