One of the most stunning moments at the 2015 Americana Music Conference’s annual awards show — a cavalcade of stars onstage at Nashville’s Ryman Auditorium, which included performances by Don Henley, Ry Cooder, Lucinda Williams, Los Lobos and others — was Rhiannon Giddens, solo, performing the traditional worksong “Water Boy.”

After a sizzling fiddle and banjo duet with Hubby Jenkins, her bandmate in the Grammy-winning Carolina Chocolate Drops, Giddens stood nearly stock-still at the microphone in a bright-red dress and unleashed a mighty holler. It was a masterpiece of passion, power and pacing that held the room entirely captive.

She sang the arrangement of “Water Boy” made famous by Odetta — who, like Giddens, was a classically trained vocalist and who also informed her folksinging with the control she had learned.

“They teach you to be relaxed and to not do a bunch of extraneous things,” Giddens explained.

“Now I have that ability do that, and I can choose to do it or not do it. I can choose to work the stage or I can choose to just stand there. A song like ‘Water Boy’ definitely is served by the focus, all of the energy in sort of just being there behind the microphone. That’s what it wants to do as a song, you know?”

Giddens had already stolen another show with her version of “Water Boy.” T-Bone Burnett had curated the ’60s folk-revival “Another Day, Another Time,” presented at New York City’s Town Hall in celebration of the Coen Brothers film “Inside Llewyn Davis.” After the singers’ arresting performance, Burnett signed up to produce “Tomorrow Is My Turn,” her solo debut for the Nonesuch label, which was released in 2014 and was nominated for the Best Folk Album Grammy award.

In the Carolina Chocolate Drops, Giddens and her bandmates mined the rural African-American string band tradition, mostly from the Piedmont region of North Carolina, for repertoire. For “Tomorrow Is My Turn,” she was flying solo, and circumscribed only by her own taste.

“The Carolina Chocolate Drops was truly excavating and exploring the earliest American music,” she said, “and when you do that, you realize that it’s all coming from the same melting pot of cultures that have been influencing each other in different ways since the beginning of the country. So much of that syncretization happened, of course, in African-American communities — that was still different cultures clashing, all the different African nations that were jumbled up together, and then European art music.

“It was mixing together, people taking what they wanted, and then white musicians altering it further and then black musicians altering that. It’s a thing that happens in American music. When I look at jazz, and blues, and country, and rock, it’s all the same to me.”

“Tomorrow Is My Turn” is a diverse platter that shows off Giddens’ versatility, both vocal and emotional. She brings sweet melancholy to Patsy Cline’s “She’s Got You” and a witchy crackle to the foreboding blues “Last Kind Word Blues,” an obscure side from the mysterious blues singer Geeshie Wiley that’s become a cult favorite — it was recorded recently by Dexter Romweber and Jack White, as a special-edition single — for its chilling creepiness.

Then there’s the smoky title ballad, immortalized in English by Nina Simone and retaining the Gallic elegance of Charles Aznavour’s original French version; an extra-groovy take on “Black is the Color,” another song associated with the imposing Simone; and, of course, the floor-shaking force of “Water Boy.” “Factory Girl,” the EP with which she followed “Tomorrow is my Turn” is another fascinating grabbag from her busy, literate mind and shapeshifting voice, including the sly jazz stomp “Underneath the Harlem Moon,” an original country frolic inspired by a moonshiner relative, and even the warbling vocal acrobatics of traditional Gaelic mouth music.

“I’m already deep in the next record,” she said. “I’ll be doing interpretations for sure, but I’ve been writing a lot. A lot of it is still going to be historically based, historically inspired. It’s not going to be a collection of pop tunes about love and cellphones. It’ll definitely be the next step.”

Rhiannon Giddens plays Jazz Fest at 3:50 p.m. on Sunday in the Blues Tent.