Eight of the songs here are worth five stars. They come from a live performance in Sweden in 1964, by which time Vaughan’s voice had darkened, she emoted more and she had lost any trace of self-consciousness while singing. The preceding 11 songs are from six years earler. Her voice was already a wonder for its range, beauty of tone and accuracy, but at 34 she had yet to mature into her finest work. Bassists Richard Davis and Buster Williams are among those accompanying her.