People often think he’s years older than he is. Offstage, he looks young, but 37-year-old Jon Steinhagen has been actively involved in musical theater for more than two decades.

Currently, he’s playing the title role of early silent film director Mack Sennett in Circle Theatre’s production of “Mack and Mabel.” Meanwhile, the latest musical he composed and wrote, “The Teapot Scandal of 1923,” has been enjoying its world premiere at Porchlight Theatre in the Theatre Building on Chicago’s north side.

Steinhagen got his start in showbiz at age 16 while he was a student at Fenwick High School. Karen Skinner, one of the founders of Circle Theatre, hired him to serve as musical director for the fledgling company’s production of “Pippin.” Circle was mounting its shows in a Forest Park church basement in those days.

“Jon was only 16 years old,” Skinner said. “But he was so remarkably self-possessed and conducted himself with such utter professionalism; we all had to constantly remind ourselves he was just a high school kid. His talent was so outstanding.

The Riverside resident, who began taking piano lessons at age 7, had already immersed himself in Broadway scores by the time he was a freshman at Fenwick. On his own he’d studied cast albums of warhorse musicals like “Pajama Game” and “Damn Yankees,” as well as the works of Cole Porter and the other great American musical theater composers.

“I learned from the masters,” Steinhagen said. “Some rubbed off on me more than others.”

In the late ’80s, while Jon was a student at DePaul University, I myself was writing plays-but never music. One of these shows, “Kick Up Your Heels,” was based on the life of a colorful actress, Grace Hayward, whose company performed at Oak Park’s Warrington Opera house, circa 1910. Steinhagen, just 19, composed all the music and wrote the lyrics.

It was easy to make these pages of history come alive at Village Players Theatre with his lively ragtime-influenced score. I remember situations where I’d meet with Jon at his dorm at DePaul to explain how we needed a particular song for a specific scene. The next day he would have the number nearly completed.

In the early ’90s, Jon and I did a comedy/mystery musical for Circle Theatre called “Vendetta.” I based the plot on the McCarthy era “witch hunt” conflicts of mid-century Hollywood. At every performance, the audience would actually be polled on which of the characters they thought was the murderer. This was great fun, but rather complicated to pull off, since the actors all had to be ready at a moment’s notice to perform “their” ending to the show.

“Jon’s such a complex individual and a totally talented musician,” Michael Termine, who directed “Vendetta,” said. “He was able to tap into the personal demons of each of the who-done-it characters. The songs sometimes grew dark, but they were always such great fun. Audiences loved Jon’s numbers, and he couldn’t have been more of a joy to work with. His gifts were immediately apparent and awesome.”

Theater-driven

At DePaul University, however, Jon was frustrated taking the basic musical theory classes and being steered toward classical composition.

“I was writing stuff for which I had no ear,” he said, admitting his own shortcoming. “Now it’s different for music students. But not so long ago anyone who wanted to write for musical theater was not encouraged or nurtured in traditional music departments.”

Jon ended up getting his degree in English.

But he continued creating his own shows, performing sometimes, serving as musical director for others. Actress and singer Sara Minton, who has worked with him several times, remembered him as musical director of Pegasus Players’ production of Stephen Sondheim’s “Sunday in the Park with George.”

“Jon was always fascinating,” Minton said. “He’s so witty and humble, always a gentleman-a brilliant lyricist, composer, pianist, and actor.”

For all their diversity, Steinhagen’s shows are often set in earlier eras. “Nobody Likes Retsina,” for which he wrote the lyrics for Philip Seward’s music, was about love, forgiveness, and the Greek Mafia of the early 1930s. “Emma & Company,” for which he composed both the music and the lyrics, was based on the “Emma McChesney” stories by Edna Ferber. That musical focused on an early 20th century divorced mother who worked as a traveling salesman. Critics called the show “lively,” “charming,” and “engrossing” when it played in New York City.

“The Tell-Tale Heart” was a one-man, one-act opera based on Edgar Allen Poe’s haunting short story.

Acclaim as an actor

Steinhagen has also received rave reviews for his acting. In Circle Theatre’s “Mystery of Edwin Drood” several seasons back, he was singled out by critics for his superior comedic timing, his articulation, and even his hilarious ad-libs. Last year he shined in Circle’s production of the film noir musical, “Sweet Smell of Success,” about the dirty world of tabloid journalism in the 1950s, in which he played a nasty, powerful columnist originally portrayed by Burt Lancaster in the film version.

“It was a very odious character and it took so much energy to be so constantly on the edge, so cynical and corroded,” Steinhagen said.

He is just closing out Circle’s production of “Mack & Mabel,” a Jerry Herman musical depicting the love affair in the ‘Teens and ’20s between innovative silent comedy director Mack Sennett and Mabel Normand, a Brooklyn waitress-turned-movie-star/comedienne. The production ended April 7.