I was not sure what to expect from “Civil War Voices” —  an innovative new musical that promised to bring to life the true stories of five individuals living during the American Civil War  — but I left the Walnut Street Theatre impressed. The musical, written by James R. Harris, is based on real diaries, letters and memoirs, while the soundtrack consists of modern arrangements of popular songs from the era by composer Mark Hayes, including “Aura Lee,” “Amazing Grace” and “The Yellow Rose of Texas.” It is a fresh look at a familiar period of history that showcases the talent of its small cast.

The characters represent the diverse viewpoints present in America during the Civil War. Joe Harris, played by Ben Sheppard, is a slaveholder with conflicted feelings about the war. Elizabeth Keckley, played by the phenomenal Jessica Johnson, is a woman who earns her freedom from slavery and works as a seamstress for the Lincolns. Theo Perry, played by Matthew Mastronardi, is a young man from Texas who leaves his wife, Harriet, played by Laura Giknis, behind when he joins the Confederate army. Damon Bonetti plays Joshua Chamberlain, a professor from Maine who becomes a Union war hero. Nicholas L. Parker acts as the narrator and brings his charismatic presence and powerful baritone voice to a variety of minor roles.

The musical is performed in the Independence Studio on the third floor, an intimate venue seating about 80. Even seated in the back row, I was no more than 20 to 30 feet away from the actors for the duration of the play. One of the benefits of this smaller venue is the level of audience interaction — the actors encourage the audience to clap their hands during some of the more upbeat musical numbers, pass out recruitment fliers during one scene and even join them in a rendition of “Battle Hymn of the Republic.”

Adding to the immersion is the set design, which encompasses not just the stage itself but all four walls and the seating. Unfinished wood beams, wood flooring and embroidered, period-accurate chairs add a rustic feeling to the venue. The stage is cluttered with antique-looking props and furniture that the actors rearrange between scenes to transform the set from a tavern to a battlefield to the White House.

The whole production has an air of barely-restrained chaos. With only six actors and a multitude of small roles — anonymous soldiers, Elizabeth Keckley’s upper-class clients and even Abraham Lincoln — the actors change identities rapidly as they move through the scenes. It might come across unclear in the wrong hands, but due to the clever use of props, costuming and acting choices, I was never lost. Not only do the actors play a wide range of characters, but they also show off their talent as instrumentalists. Mastronardi accompanies many of the musical numbers on the piano, while Sheppard and Bonetti show off their talent on the bass and guitar. Another song features Bonetti on the harmonica. Other actors play the drums, cymbals and even a slide whistle. While the musical is clearly demanding to perform, I could tell how much the actors were enjoying themselves throughout.

Not every joke lands, but there is a surprising amount of humor as well as several comedic performances interspersed with scenes that reflect the brutal reality of the Civil War. The musical just barely avoids giving the audience whiplash as it alternates between powerhouse numbers like “Sometimes I Feel Like a Motherless Child” and “Battle Cry of Freedom” that reflect the tragedy of the characters’ lives and raucous, foot-stomping songs that add a much-needed sense of levity. In the end, the show manages to strike a balance between joy and despair.

While this musical is relatively unknown, it has the makings of something great. I was impressed by the unique subject matter, the energy brought by the actors and the brilliant musical arrangements. It felt fresh and exciting without compromising historical accuracy; it was quirky but still something I can see having widespread appeal. “Civil War Voices” is an excellent tribute to the past that feels modern nonetheless.

“Civil War Voices” will be playing at the Walnut Street Theatre through May 26.