Ruthie Foster named her hollow-body electric guitar “Pearl” in honor of three famous Pearls – Bailey, Minnie and Janis Joplin – and the jazz, country and blues they represent. 

Foster brought all that and more to Dayton, Ohio’s, Levitt Pavilion for a free Aug. 8 gig. And when she momentarily abandoned Pearl and stepped to the mic to sing Son House’s “Grinnin’ in Your Face” a cappella, the venue was a temporary church; the rented lawn chairs ephemeral pews. 

Singing wordlessly like the women at her girlhood house of worship, then belting solo, Foster, arms extended wide as if she were about to embrace the entire planet, eventually ended in harmony with her bassist and drummer, eliciting a raucous ovation as Levitt organizers brought her a hard-earned drink. With that, Foster, clad in black on a steamy summer’s eve, toasted the audience and turned back to Pearl. 

The trio solos only on the mic; the playing is strictly rhythm. But when Foster is crying and singing songs from across the American musical landscape and pretending genre classifications don’t exist, that is plenty to carry an 80-minute set. 

For Foster is a rarified talent and interpreter extraordinaire, taking such songs as Mississippi John Hurt’s “Richmond Woman Blues,” Sister Rosetta Tharpe’s “Up above My Head I Hear Music in the Air,” Patty Griffin’s “When it Don’t Come Easy” and Lucinda Williams’ “Fruits of My Labor” and turning them into Ruthie Foster songs. 

And when she transformed the sunny folk of Pete Seeger’s “If I Had a Hammer” into a gritty blues of steely determination, Foster – head thrown back and wailing – transformed the audience right along with it.