It’s a few minutes before 10 a.m. on a recent Tuesday and Al Green sits on the phone line’s other end as lively as a fireworks finale. To emphasize a point, the soul legend starts singing one of his biggest hits in a delicious falsetto.

“Love and happiness,” Green begins. “Something that can make you do wrong/Make you do right …”

Green – Rev. Green, amen – insists that you can preach the gospel and perform some of the sexiest soul music ever recorded.

“That sounds like lines from a sermon,” says Green, a Memphis preacher and member of the Rock and Roll Hall of Fame. “When I wrote that song (in 1972), I wasn’t born again yet. I didn’t know that was going to be so important to me later on. But I know what each song means to me and I’m here to serve God.”

Green adds quickly that his headlining appearance at the Madison Blues Festival on Sunday, Aug. 24, won’t be a fire-and-brimstone revival meeting.

“Of course, you’re going to get the hits. That’s why I’m coming there,” Green says, practically shouting. “The man upstairs says if I don’t sing, He’s made a mistake concerning Rev. Green.”

Raised by stern religious parents, Green, now 56, was forced out of the family’s gospel group as a teen for listening to rhythm-and-blues singer Jackie Wilson. Green’s career then headed toward secular music. In the early 1970s, Green wrote and performed a string of popular singles, including “Tired of Being Alone,” “Let’s Stay Together” and the aforementioned “Love and Happiness.”

A girlfriend’s suicide in 1974 pushed Green back into the church. For the last three decades, Green recorded largely gospel music, although he had a pop hit duet with Annie Lennox in 1988.

“I don’t know if I’ve ever been pulled away from gospel music,” Green says. “I’ve been forever pulled toward it.”

In concerts now, Green offers a touch of gospel during his set. But Green’s soulful songs dominate the show. He described a recent concert in Biloxi, Miss., where women struggled for roses tossed from the stage and the crowd energized him.

“It was crazy, man,” he says, then adds, “Woooo! It was a lot of fun.”

Headlining a blues festival may seem a bit of a stretch for Green, who rarely dug deep into the genre.

“Listen to this,” Green says and plays a few bluesy chords on the guitar. “C’mon, man, that’s what makes us who we are. I love that.”

Between weekend gigs, Green is recording a new soul album. He also wants to do jazz and contemporary Christian CDs. Proud of his current tour, Green says, “This show is kicking my” – he pauses before letting a slight profanity slip and laughs – “butt.”

To assure he recreates his soulful sound faithfully, Green will be joined on stage by a 14-piece band, 4 background singers and 3 dancers. His crowds have changed over the years.

“It used to be all black,” he says. “Now it’s 60 to 70 percent white and a lot of Mexican-Americans. Then you have your soul brothers and sisters in spots over here and there. But everyone’s shouting, ‘Go, Al! Go, Al!’ ”

Green is taken aback when told he’ll perform on a stage at Olin Park set alongside Lake Monona, where Otis Redding died in a plane crash on Dec. 10, 1967.

“He was one of my favorites. Just incredible,” Green says. “Every now and then you can hear a little of Otis Redding in Al Green.”

To acknowledge Redding’s early death, Green seems to take the Madison show with a new perspective.

“We’ll be praying that we can do a good job,” Green says. “We claim everything by faith.”

Amen, Rev. Green.

“Yeah,” he says brightly, “amen.”