Imagine finding a warbling baby bird, fallen from a nest high in an oak tree. You go inside to get a shoebox to transport the helpless fledgling to Lakeside Nature Center, but you discover that, in your absence, the helpless chick has eviscerated your neighbor’s Rottweiler and is feasting on Fido’s entrails. The folk music made by Joanna Newsom is pretty much that weird and surprising. The songs from her new album, Ys, find her straying further into the realms of medieval nature-wonder and rhapsodic mystery, turning clever phrases and chirping with bloodlust. The woman has serious chops, and she’ll be taking a chunk out of The Granada on Sunday, so bring your thickest falconer’s glove.