For more than 25 years, Robert Jones has been one of the most popular and respected figures on the Detroit-area blues scene.

But for the last 10 of those years, he's been known as the Rev. Robert Jones, ever since becoming the pastor of Sweet Kingdom Missionary Baptist Church in Detroit. That calling has also prompted his music to move in a somewhat different direction.

Since becoming a pastor, Jones' blues sensibilities have understandably moved in more of a gospel-blues direction. But, more broadly, he has redefined his musical mission as one that explores what he simply refers to as "American roots music."

These days, when he gives a performance, he'll still do a Muddy Waters tune, and a Howlin' Wolf tune, but he'll also do the gospel blues of Rev. Gary Davis and Blind Willie Johnson, as well as his own compositions in the gospel-blues vein. And he'll also include songs that are steeped in the essence of the blues or gospel music, even though they don't adhere strictly to those styles—like Townes Van Zandt's "Marie," or Leonard Cohen's "Hallelujah."

He's also added storytelling to his onstage presentation. He's always liked telling stories about the artists whose songs he was singing, but he's dug more deeply into the storytelling tradition in the last five years or so.

And these days, about half of his performances are duo gigs with his wife, Bernice—known in the local gospel-music community as Sister Bernice Jones—who is a "powerful gospel singer," says Jones. Indeed, when he comes to The Ark on Sunday, it will be one of those duo shows. Robert and Bernice also recorded an album together in 2010, "Guitar Evangelists."

"Bernice brings a lot of energy to the stage when we do those duo performances," says Jones. "When I do my educational programs (more on those later), it's often just me, but when I get to do something that's purely for fun, I love to have her up there with me."

And after many years of playing in blues clubs and bars, Jones guesses that "I probably haven't played a bar gig in about 10 years. Most of my performances now are in coffeehouses, schools, senior citizen homes and at festivals," he says.

"So, my show has changed in the last 10 years, but it's not like you're coming to see a church service," says Jones. "I do music that's interesting to me, whether it's blues or gospel or traditional work songs or folk songs."

When he first took the pastor's position, one decision he made was to quit doing his "Blues from the Lowlands" show on WDET, 101.9-FM in Detroit, which aired every Saturday afternoon for about 19 years.

"One reason for that is that it takes a lot of energy to learn how to be a pastor of a church, but there was also a shift in emphasis—I became more interested in telling the truth through my music, instead of just being an entertainer."

Part of Jones' musical evolution is that he has also added fiddle playing to his show. "It was also about 10 years ago, at a music teaching camp, that I spent some time listening to Mike Seeger, and he was playing the banjo and fiddle, and that made an impression on me. I decided I'd rather be the black Mike Seeger than the short Taj Mahal," he says with a droll laugh.

"So, I taught myself the fiddle, and after a few years of torturing people with my bad fiddle playing, I became credible enough on the instrument to add it to my live shows, and that opened me up to a whole new folk-song tradition that I hadn't explored before."

On the The "Guitar Evangelists" album, Jones and his wife were "looking for a vehicle that wasn't conventional gospel music. Usually, when we think of gospel, we think of it being piano-based, but we wanted to draw on older traditions, and go back to the era where the principal instrument was the guitar."

Jones' latest album, released last summer, is "Soul of a Man," which is in part an homage to the likes of gospel-blues pioneers like Davis and Johnson -- but also features a couple of more recent works, as well as "some cool public-domain stuff that I came across that I wanted to have some fun with."

Songs include classics like Davis' "Samson and Delilah," Johnson's "What is the Soul of a Man," Skip James' "Hard Time Killing Floor Blues," J.B. Lenoir's "God's Word," Bill Morrissey's "Robert Johnson," a Jones composition titled "The Question" -- and an 11-minute-long excerpt from one of Jones' sermons.

Jones also devotes a fair amount of time presenting his educational program in schools and to senior citizen groups and other community groups. He did that for many years with his longtime music pal, Detroit-area folk singer Matt Watroba, but that slowed down in '09 after the Great Recession hit, and school budgets were slashed. Then, in '10, Watroba moved to Ohio to take a full-time job as a program host on FolkAlley.com.

So, Jones now mostly does the educational program on his own, but sometimes still does it with Watroba or other local writers / musicians like M.L. Liebler and Peter Madcat Ruth.

"The spine of that program is the blues, because the blues is also the spine of American music," says Jones. "Almost every form of American popular music can trace its roots back to the blues.

"So, in the program, I talk about how important the blues tradition is, and where the blues came from—which, of course, was the music of African slaves. But they didn't call it blues at the time: They had two basic styles of music—what they called 'moans,' which were the slow songs, and the 'reels,' which were the faster songs. I emphasize that African music changed American music."

Kevin Ransom is a freelance writer who covers music for AnnArbor.com. He can be reached at KevinRansom10@aol.com.