Gaelynn Lea’s voice and violin land like a balm — an offering of both clarity and gladness that can still be mustered in this midwinter, this upended Christmas season. She first came to the attention of many when she won NPR Music’s Tiny Desk Contest in 2016. This fiddler and singer-songwriter moves through the world in an electric wheelchair, and plays the violin like a cello because of the disability she was born with — a genetic condition that has made her bones more breakable. So much of what she’s learned through life in her body lands as wisdom, right now.