48. "Ronan" (2012)
A little-known charity single for cancer research, unlike anything else in her songbook. She wrote this about Ronan Thompson, a four-year-old Arizona boy who died of neuroblastoma, after she read his mom's blog. She turned the blog entries into a disarmingly eloquent ballad (crediting Maya Thompson as co-writer) and performed "Ronan" at the Stand Up to Cancer benefit. You might expect it to be manipulative and obvious; it isn't.
Best line: "We had our own secret club."