The vocal choir ChoralArt rehearsing “Fire!” at Woodfords Congregational Church. Shawn Patrick Ouellette/Portland Press Herald

Travis Ramsey says it began with the kind of request that “all composers dream of.”

The director of ChoralArt in Portland was asking him to write half a concert’s worth of music about anything he wanted,  as long as it had a strong Maine connection. After mulling over a few ideas, Ramsey’s wife told him about a Portland Press Herald web page devoted to Portland’s Great Fire of 1866.

“My brain was figuratively lit on fire with the possibilities — great personal accounts, photographs, poetry and letters,” said Ramsey, a 2003 University of Southern Maine graduate who lives in Etna, New Hampshire.

ChoralArt will present Ramsey’s 30-minute oratorio “Fire!” at Woodfords Congregational Church in Portland at 2:30 p.m. on Saturday and Sunday. The performance will feature about 40 singers, a vocal quartet and nine instruments. Tickets are $29 to $44, free for students and children under 12, and are available at choralart.org or at the door.

ChoralArt has commissioned pieces before, but usually for Christmas concerts, said Robert Russell, the organization’s music director. This is the first piece the group will do based on Portland history. At 30 minutes, the piece is about four times longer than most things the group has commissioned, Russell said.

Russell also asked that any piece Ramsey created would use the same instruments as the Mozart work “Credomesse,” which will also be performed at the concerts.

“When Travis came back with the idea about the fire, it floored me, I thought it was amazing,” said Russell, professor emeritus of music and choral studies at the University of Southern Maine. “He turned that idea into quite a remarkable piece.”

ChoralArt music director Robert Russell conducts a rehearsal of “Fire!” at Woodfords Congregational Church on March 10. Shawn Patrick Ouellette/Portland Press Herald

Founded in 1972, ChoralArt is a Portland nonprofit that maintains three ensembles, with singers mostly from southern Maine and Greater Portland.

There will be a lecture about the fire and the city’s recovery before each concert, at 2 p.m., by Portland historian Herb Adams. The ChoralArt website also has a prerecorded lecture by Maine State Historian Earle G. Shettleworth Jr., so concertgoers can get some background about the fire beforehand.

THE GREAT FIRE – IN MUSIC

Looking up Exchange Street from Fore Street. The Custom House appears almost undamaged from the Great Fire of 1866, but the intense fire weakened the structure and it was taken down and replaced with a post office while the Custom House was rebuilt at its current location on Fore Street. Photograph by S.W. Sawyer — Photo courtesy of the Maine Historic Preservation Commission

The Great Fire in Portland started on July 4, 1866, near the harbor. The fire swept across the city’s peninsula, destroying more than 1,500 buildings and leaving more than 10,000 people homeless. The fire would lead to national reforms about fire safety and reshape the city.

To research his piece, Ramsey, sought out a variety of sources, including Abner Harmon’s poem written soon after the fire, and a letter written by Maine-born poet Henry Wadsworth Longfellow. He also read books about the fire, the personal dramas and tragedies, and the aftermath. These included “The Night the Sky Turned Red” by Allan Levinsky and “Portland’s Greatest Conflagration” by Michael Daicy and Don Whitney.

The first movement of the piece focuses on the Fourth of July celebration, with joyous marches and hymns shifting to the sounds of alarm bells, and then to a fast-paced, frenetic passage as firefighters struggle to contain the blaze, Ramsey said.

Part of the chorus includes the lines: “The fire broke out July the fourth, at five in the afternoon; And sealed the celebration of independence soon; Our national independence, in which we all delight; Became a scene of excitement, desolation, fear and fright.”

The second movement, sung a cappella, is about the destruction and desolation caused by the fire. The third movement, featuring the vocal quartet, is about letters sent to Portland from a variety of people trying to help, including the leader of a soldier’s aid society and a boy collecting coins for the cause.

ChoralArt Music Director Robert Russell conducts vocal choir ChoralArt as they rehearse “Fire!” at Woodfords Congregational Church on March 10. Shawn Patrick Ouellette/Portland Press Herald

The final movement includes hymns about the rebuilding of the city, including its churches and includes the lines: “Now, let us do our work as well the seen and the unseen; Make the house where Gods may dwell beautiful entire and clean; Else these lives are incomplete when standing in these walls of time; Broken stairways as the feet will stumble as they try to climb.”

Ramsey said his biggest challenge was getting the right balance between narrative and emotion in the first and fourth movements.

“I wanted to tell the story of the fire and I wanted to show how apocalyptic it must have felt. Too much of the former would feel dry and textbook-like, too much of the latter would just be people screaming,” said Ramsey. “The fourth movement was hard, too, because the hymns are so simple in structure. I wanted them to sound fresh and new and compelling, but also not be total anachronisms to the music of the 19th century.”