You could say that Henry Howard Holmes was the personification of the phrase "evil genius." A doctor living in Chicago in 1893, when the city hosted the World's Fair, he built what has since been described as a murder castle. Holmes designed a hotel with secret features he'd use in his planned killings, and he lured some of his victims from that famous fair. He became America's first documented serial killer, although the exact number of his murders could never be confirmed - anywhere from nine to 200 are totals that have been bandied about.

While the fair was celebrating new technology, Holmes used some of those innovations in his nefarious scheme.

The story fascinated both Julia Gytri and Avi Amon. They loved reading a bestselling book about it all, Erik Larson's "The Devil in the White City."

When librettist Gytri and composer Amon collaborated at New York University's Tisch School of the Arts in 2011, they began working on a musical about that subject. They didn't adapt "Devil in the White City" but instead did their own research at historical societies and in archives in Chicago and New York City.

The resulting piece, titled "The White City," was selected as one of two shows to be developed at this year's National Music Theater Conference at the Eugene O'Neill Theater Center in Waterford.

"We kind of created our own fictionalized version of this history," says Amon.

Gytri says their way into the story was through Holmes' three wives. He was living a trio of different lives, and his spouses knew nothing about each other - or about his murderous ways.

The central character of "The White City," though, is a fourth woman, a mostly fictional character who is a sharpshooter in Buffalo Bill's Wild West Show.

While "The White City" does deal with the serial killer story, it also delves into the momentous World Fair and the transformative era. This was a time when, Gytri says, "the foundation of all the new technology we see in the 20th century is happening."

Amon adds, "Imagine hundreds of thousands of people seeing electricity for the first time."

When people ask what they're writing, Gytri says, "You lead with 'A serial killer show,' but the show really is about technology and how you introduce life-altering technology into society, expecting it to only produce great results. But someone with the right mind set and set of skills can take it and do something completely different with it."

The original drafts of "The White City" didn't have Holmes sing, but the duo were advised to change that. What they ended up doing in his numbers was to reflect some of his personality flaws.

"He's so smooth, and he can appropriate anything and be, like, 'This is mine,' because that's what he felt he deserved," Amon says. "We wanted him to sound like he had heard something at the fair and (thought) 'This is my song now.'"

His sound echoes the 1890s pop vernacular, with a pre-Tin Pan Alley/player piano feel. The rest of the score pulls from various styles, with a lot of 19th-century romantic music as well as some bluegrass and old-style country influences to reflect the story's Buffalo Bill element.

As for the backgrounds of "The White City's" creators: Gytri, who describes herself as an Air Force child, finished high school and got her undergraduate degree in Austin, Texas. She studied playwriting and physics - playwriting because she loved doing it and physics because she was good at it. She wanted to find something that she'd both love doing and was good at; she discovered collaborating on musical theater.

Amon, meanwhile, grew up in Rochester, N.Y., and graduated from the University of Delaware, majoring in economics and history. He spent three years after that as a college admissions counselor but quit and reassessed his life. Growing up, he had studied classical piano, and he wrote music on occasion.

"I feel like I was saying music was a hobby my whole life but was treating it like it was a job, in terms of the amount of time and energy and care that went toward it," he says.

Realizing that, he decided to really focus on music.

Amon and Gytri met as students at NYT's Tisch School and graduated last year. Besides developing "The White City," she has been writing and performing children's songs for a childhood enrichment company, and he was arts and ideas program coordinator at the Jewish Community Center in Manhattan.

Now, not only are they spending time at the O'Neill working on "The White City," but they are also getting to hear the full piece performed for the first time. There was a reading when they were finished graduate school, but that was only 90 minutes of a musical that runs at least two hours.

"Just seeing and hearing it alone, even if we weren't allowed to do rewrites or anything, would be a huge gift," Gytri says.

k.dorsey@theday.com

If you go

What: "The White City" by Julia Gytri and Avi Amon

Where: Eugene O'Neill Theater Center, 305 Great Neck Road, Waterford

When: 8 tonight, 3 p.m. Sunday, 8 p.m. July 9, and 3 p.m. July 11

Tickets: $28

Contact: (860) 443-1238, theoneill.org