When we think of the blues, rural crossroads come to mind. Or maybe roadhouses, or at least sweaty clubs longer on ambience than niceties.

Office buildings and imposing architectural structures seem antithetical to music that almost always comes with a down-home ambience, but Lafayette Square downtown is the home of the Crescent City Blues and Barbecue Festival. This weekend, it will be down-home enough.

It helps that the space also is the home of Wednesdays in the Square, so people have come to think of it as a music space. It’s also nice that it’s not too big.

“It’s not the Jazz Fest. I can look at the people; they’re 8 feet away,” Marcia Ball said. Ball will follow Walter “Wolfman” Washington and headline the free festival Friday night, and she’s comfortable in Lafayette Square because she plays it every May around Jazz Fest. The space also has significance for her besides her own experiences with it during Mardi Gras and as a performer.

“My cousin worked at the courthouse for a long time, so I always think of her,” Ball says, referring to the building that borders Lafayette Square on Camp Street. “My mother went to business school in New Orleans after she got out of high school, and she always talked about walking, riding and roller skating past the park and the courthouse.”

The New Orleans Jazz and Heritage Foundation produces the Crescent City Blues and Barbecue Festival, which presents music on two stages all weekend long.

This year’s lineup is a mix of local and national artists that cover a broad swath of the blues. Highlights include the legendary Swamp Dogg, Ruthie Foster, and a New Orleans blues and R&B set with The Funky Meters, Allen Toussaint and Irma Thomas.

Sunday night, the festival ends with the Excello Records Reunion, which brings together Louisiana blues artists Lazy Lester, Carol Fran, Classie Ballou and Lil Buck Sinegal.

Young Mississippi blues guitarist Jarekus Singleton will make his debut at the festival Sunday afternoon, but it will be his fourth gig to New Orleans in the last two years. He last performed here during Jazz Fest, and he’s excited to return.

“The people in New Orleans, they appreciate good music,” Singleton said. “I love coming to New Orleans to play. The people there are very attentive, they cooperate and they get with the program.”

Singleton has worked the 2015 festival season for all he could get, playing more than 45 this year. He credits those appearances with exposing him to a wider audience.

“That has helped my status a lot,” he said. “It’s helped record sales, and it’s helped word of mouth. When those same people from the festivals come and see you in the venues, that’s a beautiful thing.”

It’s a slightly different experience for a veteran performer like Ball. Gigs like these are often gatherings of her tribe, and she quickly knows how diehard the crowd is by how far back their requests go. “When people start calling out for our songs —‘La Di Da’ or ‘Louella’ or ‘That’s Enough of that Stuff’ — then I know that’s my people,” she said.

Singleton and Ball agree that the atmosphere is what you make it, and daytime in the Central Business District can be as soulful as any juke joint if you do it right.

“Whether the sun is up, whether the sun is down, whether the moon is up, whether it’s raining outside, if I have one person out there paying attention, I feel so much love,” Singleton said.

For Ball, playing in the daytime means she can easily gauge how she’s doing.

“You can see faces for quite a way,” she said. “I’m not one of those people who picks someone out and sings right at them. Recently, a woman in the front row was singing every word to the song I was singing. That’s encouraging!”