Award-winning sexagenarian female guitarist and blues singer who learned how to conjure the grime so essential to her trade from the sorts of Delta bluesman that usually can’t be heard without a field recorder and a sturdy pair of hiking boots — most notably John Hurt, but also Son House and Robert Johnson, the latter being the subjects of her recent tribute albums. No definitive word yet as to whether she had to sell her soul to the devil in order to accomplish all this.