DENNIS – The pine-paneled lobby of the picturesque Cape Playhouse is filled with old photographs and mementos of theater days gone by — Henry and Jane Fonda perched on a fence on the grounds, flashy cars from the early ’60s parked on the lawn, Shirley Booth’s 1953 Oscar. One of the first summer theaters on Cape Cod, the playhouse is marking its 90th anniversary season.

Theater has a long and proud history on Cape Cod. It has been 100 years since the Provincetown Players staged the first production of a Eugene O’Neill play, an event widely considered the birth of modern American theater, notes David Kaplan, executive director of the Cape Cod Theater Coalition. While many of the coalition’s 26 member theaters offer year-round programming, there’s a definite burst of theatrical energy in summer, bolstered by companies of young, up-and-coming performers, which can be a pleasant and sometimes nostalgic addition to summer vacation.

The Cape Playhouse has nostalgia in spades, with its weathered shingles, broad striped awnings, and curlicued gazebo. Bette Davis first worked here as an usher before returning the following summer to act. Gregory Peck, Humphrey Bogart, and Robert Montgomery all performed on this stage. The cavernous interior and arched windows recall a meetinghouse, which is exactly what the building was before Raymond Moore turned it into a theater in 1927. The pews have been softened a bit with deep red cushions.

Managing director Mimi de Quesada describes the season as “a perfect mix of productions,’’ with musicals, classics, and new works, such as “The May Queen,’’ which started two years ago as a reading and opens this week as a full-fledged production.

An exhibit at the Cape Cod Museum of Art, on the same campus as the playhouse, celebrates the theater’s storied history. “Sand, Stage and Stars: 90 Years of Summer Theater by the Sea’’ continues through Aug. 10.

If visiting the Cape Rep Theatre in Brewster feels a bit like going to camp, that’s because the 7-acre property within the boundaries of Nickerson State Park used to be a summer camp. The 129-seat indoor theater, which stages five plays from May through December, was the dining hall, and a 200-seat outdoor venue in an oak and pine grove, now used for children’s productions in summer, was the chapel. Work continues on two other camp buildings – a barn, which will become another performance space, and a house, which will eventually provide housing for actors, said Jared Hagan, who handles marketing.

Using professional as well as local talent, the theater tries to be artist driven, Hagan said. “We use a lot of the same actors in our productions. We try to be as much of a repertory company as we can.’’ Cape Rep offers a mix of classics, musicals, and new work. “Hairspray’’ opens Aug. 3. Children’s productions include “Pitter Patter Puppets’’ and “A Year with Frog and Toad.’’

One of the Cape’s newest theaters is Harbor Stage Company, an intimate 90-seat venue on Wellfleet Harbor with views of Mayo Beach and Great Island. Patrons are welcome to take a glass of wine onto the beach before the show or at intermission.

Founded five years ago by actors who met while performing with the Wellfleet Harbor Actors Theater, Harbor Stage is an artist-run company that focuses on making theater affordable (all tickets are $23). The principals – Robert Kropf, Stacy Fischer, Jonathan Fielding, and Brenda Withers – act, direct, write, and run the box office.

“Theater should be a regular part of your life,’’ says Withers. “Part of that is tickets, and part is the kind of plays we choose.’’

“The Kritik,’’ a comedy by Withers, continues through Aug. 6, followed by the regional premiere of “The River,’’ a British play that featured Hugh Jackman on Broadway.

Music fills the air outside the rambling and a little-worse-for-wear mansion that houses The College Light Opera Company in Falmouth. Inside, some 60 singers, musicians, and technicians race against the clock preparing to perform nine musicals and operettas in eight fleeting summer weeks. Each year the company is selected from applicants studying theater across the country and around the world. This year’s members hail from Emerson College, Lawrence University, the Eastman School of Music, Carnegie Mellon University, and the Oberlin Conservatory, among other institutions.

Company members live on campus for the summer, where they train with professional staff, and perform at the historic 1876 Highfield Theatre in Falmouth. “It’s pretty intensive,’’ notes Juliana MacLachlan, the group’s publicist, explaining that performers might be rehearsing an operetta all afternoon and learning the music to a modern musical that night. A full pit orchestra accompanies each production, and the performers do not wear microphones.

“Our nine shows follow a three-three-three format,’’ says artistic director Mark Pearson. “Three classical pieces, three golden-age musicals, and three more modern productions.’’ In addition to providing shows that will appeal to audiences, the company strives to give students a chance to become familiar with a variety of genres.

It’s a demanding schedule. “The Merry Widow,’’ a Viennese operetta, opens this week. And next week the same actors and musicians will perform “Gentlemen Prefer Blondes,’’ a first for the company. The difference in the two productions, says Pearson, “is night and day.’’

The Monomoy Theatre, marking 81 years in Chatham, is another training ground for musical theater students. Affiliated with Ohio University for many years, it now hosts students from the University of Hartford. Artistic director Alan Rust, who first came to Monomoy as a graduate student 44 years ago, says it’s “kind of like the Cape Cod Baseball League, only for theater.’’

The focus is on variety. The repertoire always includes one large musical, one small musical, one Shakespeare, and everything in between. “My colleagues like to joke that I’m the only producer in the world that does ‘The Music Man’ one week and Ibsen the next,’’ Rust says with a laugh.

Rust is particularly enthused about this season’s final production, “Johnny on the Spot,’’ opening Aug. 23 – and not just because he’s going to be in it. Written by Charles MacArthur, who also wrote “The Front Page,’’ this 1941 play takes an irreverent look at the absurdities of elections and campaigns. “It’s really funny,’’ Rust says, “just about as funny as the real thing we’re living through.’’

Ellen Albanese can be reached at ellen.albanese@gmail.com.