Mavis Staples is a living legend of soul, but it’d be unfair to look at her music as a relic of the past. In fact, with the help of her producer Jeff Tweedy, Staples is bringing soul, gospel, and classic R&B into the 21st century. Her latest collaboration with Tweedy, One True Vine, is a perfect example of the exciting things that Staples is doing at this point in her career: it’s a classic-sounding record that is grounded in the present, making it as vital a record now as it would have been at any other time. Still, the best way to hear Staples is in person; you have to see her using that unspeakably powerful voice to believe that a human being could sing like that. City Winery is going to be the place to be when Mavis is in town.