SALEM — “Love Letters,” which will be at Salem Theatre Company tomorrow and Saturday, is a play about two old friends, and it features two old friends in the leading roles.

Not only have the actors, John Archer and Patricia Zaido, known each other for years, but their parents were friends.

“They used to play golf together for many years at Salem Country Club,” Archer said. “They were old friends, generations ago.”

Archer, a businessman, philanthropist and supporter of the arts from Danvers, and Zaido, who ran the theater department at Salem State for decades and is now director of The Salem Partnership, are staging this performance to help support the Salem Theatre Company.

It’s a fitting project for the pair, because their friendship has always included involvement in local theater.

“The way I really came to know John was in the ’70s, when we first started the theater program at Salem State,” Zaido said. “When we were doing productions, before we had theater majors to take all the roles, John was one of the community people we used in plays. He’s a very talented man.”

Though Archer said his primary interests are singing and dancing, and he often performed in musicals at Salem State, he has appeared in “Love Letters” several times.

“It’s the story of being human, from joy to great sadness,” he said. “It’s really well-written. The more I see it and hear it, I realize there’s a reason this play has been around.”

For Archer, the play’s success is explained in part by the special value of old friends, people we have known for a long time and who also know us well.

“The constant they have is themselves,” he said. “That’s a lovely thing to have in life. There’s nothing more exciting than new friends, but nothing better than old friends — nothing more rewarding.

“You don’t have to explain everything. You’re really out there yourself, without any fringes of falsehood or make-believe.”

Written by A.R. Gurney and first performed in 1988, the play follows the exchange of letters between two characters, Andy and Melissa, over the course of their lives. From childhood through adulthood, they share intimate details, funny stories and strong feelings, while also discussing their own relationship.

Though they enjoy privileged backgrounds, the things they divulge are common to everyone.

“I hope the audience doesn’t stereotype the characters,” Zaido said. “The play introduces universal messages about men and women, and how we cope in this world.”

The play was written to be performed without rehearsal, memorization, sets or costumes, but Zaido and Archer still sought direction, from Aimee Oliver.

“We’ve seen it with direction and without direction,” Zaido said. “We’ve always felt those with direction do better. The director tells you, ‘Enjoy it more, you look stiff,’ things like that.”

The early letters are written by children and the later ones by adults, so Oliver tried to help the actors remember how differently they think and feel at each stage of life.

“You help the actor relate to it so it becomes more natural,” she said. “You want to bring the audience in to the point where they feel they are in the room with you.”

Working with Oliver allowed the actors to perfect their timing, which — in a play where they don’t move on the stage — is an important part of the story’s development.

Some letter excerpts are lengthy, sharing news or arguing a point, while others respond to a previous letter with the give-and-take of a conversation in real time.

“There are dots in the script, to show that time passes between letters,” Zaido said. “We decided to count to six. The director had to teach us to slow that down.”

When the characters respond to letters as quickly as they receive them, the exchange onstage speeds up.

“There are certain lines where we fall all over each other, we don’t finish our sentences,” Zaido said. “Timing is a key element.”

Oliver, who trained at the American Academy of Dramatic Arts, has been involved in community theater on the North Shore for 38 years. She has directed Archer in a number of plays, including “Love Letters” several times, but this is the first time she’s worked with Zaido.

“Patricia is a brilliant woman and takes direction very well,” she said.

After Zaido and Archer decided to do “Love Letters” together last year, they both agreed that their performance should benefit Salem Theatre Company.

“I always thought it was wonderful, the things they do there, and they’ve been doing it for 10 years,” Zaido said. “I thought maybe if we could fill the house for two nights, we could raise some money for Salem Theatre Company, and we would bring people to that theater who haven’t been there before.”

“Love Letters” is part of the Salem Theatre Music & More Series, which will continue Friday, March 1, with Montana Skies, a guitar and cello duo; folk musician Shaun England on Friday, March 8; and acoustic rock duo Bird Mancini on Saturday, March 9.

IF YOU GO What: @boxText_Bullet:"Love Letters" by A.R. Gurney, with John Archer and Patricia Zaido To benefit:@boxText_Bullet: Salem Theatre Company When:@boxText_Bullet: Tomorrow and Saturday, 7:30 p.m. Where: @boxText_Bullet:Salem Theatre Company, 90 Lafayette St. Tickets: @boxText_Bullet:$25, available online at www.salemtheatre.com, by phone at 978-790-8546 or by email at info@salemtheatre.com