If comedians Abbott and Costello were still around to update their classic “Who’s on First?” for the Maine Shakespeare Festival, they might create another hit called “Who’s in Rehearsal?” “What” would be building sets while “I don’t know” was feverishly sewing costumes or proofreading programs.

The backdrop would be the sets – separate and distinct, of course – for this summer’s festival scheduled for July 17-Aug. 18 on the waterfront in Bangor.

This year’s offerings, to be presented on a rotating schedule, are Shakespeare’s “King Lear” and “Twelfth Night,” and Carlo Goldoni’s “Servant of Two Masters.” In addition, Antoine de St. Exupery’s “The Little Prince” will be performed at the Bangor Opera House beginning Friday.

With 72 staff members involved in the four productions, “it’s a really labyrinthine rehearsal schedule,” said Mark Torres, artistic director for Penobscot Theatre Company and MSF.

Intricate charts keep track of who’s where and what they’re doing, and ensure that each play gets its share of rehearsal time at Brewer Middle School.

Torres will direct “King Lear,” the famous Shakespearean tragedy, with none other than Ken Stack in the title role.

Stack is a fixture in eastern Maine theater as both an actor and a director, and is most familiar to PTC audiences in his frequent role as Ebenezer Scrooge in “A Christmas Carol.”

“We are glad to have him,” Torres said. “He is a really fine actor – a professional, and a gentleman.

“Anyone familiar with the scope and depth of Ken’s talent knows what passion he will bring to the Maine Shakespeare Festival stage and how memorable he will make King Lear,” he said.

The challenge in directing “King Lear,” Torres said, “is to stay focused on the storytelling. It’s a literary jewel, basically a story of a man who kind of loves and hates too much. That seems to be the case with each of the major characters.”

Among those joining Stack on stage will be Sara Valentine as Goneril, Jennifer McEwen as Regan, Kate Kenney as Cordelia, Harold Withee as the Earl of Kent, Jay Doolittle as the Earl of Gloucester, Ben Reigel as Edgar, J. Fitz Harris as Edmund and Alex Gunn as the Duke of Cornwall.

The comedy this year is “Twelfth Night,” the story of twins Viola and Sebastian, shipwrecked on the coast of Ilyria. There are numerous romances, not to mention Shakespeare’s traditional use of gender confusion – Viola disguises herself as Cesario.

Jennifer McEwen will portray Viola, and Matthew Ferraro is Sebastian. Kathleen Cooney will be Olivia, Kenny Volock portrays Toby, Ben Reigel is Orsino, Jay Doolittle is Malvolio, Sharon Zolper plays Maria, and Alex Gunn will be Sir Andrew Aguecheck.

Speaking of gender confusion, Goldoni’s “Servant of Two Masters” features a woman named Beatrice who disguises herself as a man to search for her lover.

Collene Frashure takes the part of Beatrice, while Ben Reigel will play Florindo. J. Fitz Harris is central figure Truffaldino, Sara Valentine is Smeraldina and Alex Gunn plays Silvio.

The Shakespeare and Goldoni plays will be performed on the waterfront, while the Bangor Opera House on Main Street will be the site for the children’s classic, “The Little Prince.”

Jennifer McEwen will play the prince, while Michael Weiselberg is the pilot. Katrina Toshiko is the rose, and J. Fitz Harris the fox.

The directors for the summer all have experience in Bangor productions. In addition to Torres, who is working on “King Lear,” there is Patricia Riggin, directing “Twelfth Night.” She was the director for “Pride’s Crossing” last year, and for “Coastal Disturbances” this spring.

At the helm for “Servant of Two Masters” is Matthew Arbour, who also directed “Hamlet,” “The Turn of the Screw” and “The Importance of Being Earnest.” Laura Schutzel is directing “The Little Prince.” She also led “A Christmas Carol” in 1997 and has acted with PTC.

“They’re all familiar with Bangor. You need that kind of shorthand in the summer” when the schedule is so full, Torres said.

Upstairs at the Bangor Opera House, several of the eight sewing machines are whirring as staffers craft costumes with the guidance of Ginger Phelps, resident costume designer.

The plays span more than a millennium, explained Phelps, who has a special interest in historical projects.

“One of the things I love is the research part of it,” she said. Posted around the work space are the fanciful drawings she has created for Truffaldino’s colorful costume with its myriad of triangles.

“When I’m at home in the dead of winter, this is the world of ‘I’ll find anything,'” Phelps said with a laugh. In truth, the cloth she had in mind doesn’t exist, so it had to be put together from small pieces.

Phelps steps to one of the costume racks and pulls out the striped tights the Fool will wear in “King Lear.” That material, too, had to be assembled from individual striped pieces.

Phelps also points out some of the rich fabrics and accessories such as the piece of bear fur that will decorate a garment worn by the king of France.

“A lot came in on donations,” she explained, after PTC’s request for material ran in Joni Averill’s community column in the Bangor Daily News.

“It makes a huge difference with the community supporting us that way,” Phelps said. The designer has years of experience working with PTC and the Maine Shakespeare Festival, but downstairs, someone new is hard at work readying the floor that will be used in “The Little Prince.”

Rob Berry, a master’s degree candidate at Wayne State University, is designing the sets and lighting for all four plays this summer.

The “raked stage,” which tilts slightly toward the audience, gives patrons a better view of the actors, he explained.

Berry’s drawings of each set show simpler backgrounds than what has been used in previous years – fabric panels for “Two Masters,” a Stonehedge effect for “Lear,” a gazebo for “Twelfth Night.”

“I don’t like a lot of stuff on stage because I like actors,” he pointed out. Of course, he doesn’t do all the building and setup himself. The intricate charts that tell the actors when to rehearse also allow time for them to work on sets or costuming or other tasks.

Berry’s work is done on the stage, under the stage, behind the stage – close to where the action will be. But what’s in his mind is what the patrons will see, and how the sets will help convey the mood of the play.

“That’s our job,” he said simply, “to be the audience.”