Writer/director J.B Eckert was briefing cast members on how to take the stage for their presentation of “Pirates of Harrison Bay,” explaining how they should arrange themselves.

“And then,” he began his next sentence.

“And then we knock their socks off,” interjected Mark Henderson, one of the actors.

Eckert couldn’t agree more.

“This is going to be special,” he said.

With Eckert’s help, Sojourn Adult Day Services is putting on a show that it hopes will be hard to forget. The Mound facility is teaming with the Old Log Theatre to present what is believed to be a first-of-its-kind public performance of an original radio drama starring senior citizens with memory loss, Alzheimer’s disease or dementia.

“Sojourn is 31 years old, and in those 31 years we’ve never done anything like this before,” said Kari Johnson, the center’s program director. “No one has. To our knowledge, this is the first time anyone has put on a show in which the whole cast has variations of memory impairment.”

The issues range from “people who are just starting this journey to some who have lost an extensive amount of memory,” she said. “Everyone is dealing with some memory loss, but they’re saying, ‘Let’s still do this play.’ ”

The free show, which is at 1 p.m. Tuesday, is unique for another reason: It has not been tailored for its cast.

“It’s a regular radio script that was written for regular actors,” Eckert said. “They have to pick up on the prose; they have to pick up on the cues. And it goes fast. This was not adapted for them in any way — and they’re making it work.”

The show grew out of one of the center’s weekly activities, which is built around the radio shows of the 1930s and ’40s. Some of the participants thought it might be fun to try their hand at radio acting.

A daughter of one of the participants had worked with Eckert at the University of Minnesota, where the longtime broadcasting veteran produced weekly radio and TV programs. She reached out to him for help, and he showed up at the center one afternoon with a stack of old radio scripts ranging from the “Lux Radio Theater” to “Fibber McGee and Molly.”

“I brought them a little bit of everything — drama, mystery, romance,” he said. “Then, at the end, I said, ‘Well, I have one more. It’s a story I wrote myself.’ ”

It was an immediate hit.

“We all read it and we cried,” Johnson said. “We said, ‘This is us. This is who we are. This embodies our values.’ ”

Set on the shores of Lake Minnetonka, it’s a story about a friendship between a boy and an old man. The boy rarely looks up from his cellphone until the man introduces him to the power of imagination. If he imagines hard enough, the man promises, he might even see the pirate ship that sometimes plies the foggy bay.

Performance primer

The show will be staged the way the original radio serials were, meaning that the actors will be working from their scripts, which are now covered with notes they’ve made to themselves about the intonations and pacing of their lines. The one allowance being made for the 21st century is that the actors will be equipped with wireless microphones.

Anticipating that many of the audience members will be too young to be familiar with radio plays, Eckert is going to start the 45-minute show by outlining what’s about to happen.

“For starters, I think I’ll have to explain why the boy is being played by a woman,” he said. “This is voice work. If it [the gender reversal] bothers you, close your eyes.”

Geri Bosch is the one tackling the role, and she’s confident that she can handle it.

“I have five grandsons all that age,” she said of her character, who’s described in the script as being 7 or 8. “I know that I need to bring a little exuberance to this. A couple of the boys will be there, and they’ll see how much Grandma enjoys being like them.”

The play has 10 speaking roles. There also are 10 people in the chorus, plus another five in the orchestra.

“Everyone who wanted to be involved is doing something,” Johnson said.

That took a little creativity. For instance, a role written for one narrator has been divided into four parts. Eckert was happy to make the accommodation, but that was the only one he was willing to indulge. He made it clear from the outset that, as far as the performance was concerned, he wasn’t going to cut anyone any slack.

During a rehearsal last week, he jumped in unhesitatingly, having the actors repeat lines until they got the inflection the way he wanted and running scenes over multiple times because someone was a beat late in picking up a cue.

Johnson has been thrilled by his tough love.

“We get to see a real director treat them as real actors,” she said. “My insides jump for joy when I see that. These people don’t want their dignity to be compromised.”

Karon Durhum, who plays the boy’s mother, said she’s proud to be in the show.

“It makes me feel that I can give something back to people,” she said.

Robert Breen, one of the narrators, is coming away with a new appreciation of the effort necessary to hone a performance.

“It takes a lot of practice,” he said. “And you really have to pay attention to the script” or you’ll be late delivering a line.

The work is paying off.

“They’re doing this stuff,” Eckert said excitedly. “And they’re doing it well. Their families are going to see them up on stage performing, and, when it’s over, they’re going to give them a standing ovation.”