If this is morphing into a thread about other female vocalists that are up there, I would include Johnette Napolitano. People might not have heard of her or not like Concrete Blonde's music, but she has an impressive set of pipes. Kind of scary like Joan Jett.
Here are some covers of songs people will have heard before. The Leonard Cohen cover was an impromptu change to acoustic because of gear problems. They winged it with just a guitar. They do a nice job with the Hendrix cover. She really gets theatrical on stage.