On a recent cloudless day, 32 British tourists stepped off a tour bus in Central City and, for reasons not immediately obvious to bystanders, spread out to view a dull yellow shotgun double at 2309 First St. The plain house sat vacant, stripped of all its architectural ornaments, and with its doorways and windows covered with plywood. Its maroon cement stoop provided the only contrast.

The group had flown 4,500 miles to see this undistinguished place, along with a few others, just before the city’s signature New Orleans Jazz and Heritage Festival, which kicks off today.

Perhaps a few imagined its former occupant, the great Buddy Bolden, a cornetist widely acknowledged as the first great jazz musician, playing on that very stoop more than a century ago.

David Martin, an amateur jazz cornetist from Devon, was both thrilled and dismayed.

“I find it incredibly depressing,” he said. “You have this picture in mind of areas you’d expect to see, and all you see is crumbled stuff, very, very shabby. It’s very depressing really. On the other hand, it’s a very, very moving experience for me.”

The house, like others on a small triangular plot, belongs to Greater St. Stephen Full Gospel Baptist Church, which purchased it in 2008, not knowing its history. It has been vacant since then.

The church says it plans to bring the house back to life in a way that will honor Bolden’s legacy — “more than just a plaque on the house,” spokeswoman Angela Young said.

That such a powerful cultural landmark could be so long boarded-up and out of commerce is a worry not only to English jazz lovers but also to American music historians and proud locals who want to save the few remaining places associated with the New Orleans birth of a global art form.

There aren’t many left.

Louis Armstrong’s birthplace lies under the Municipal Court Building on South Broad Street; the site of his boyhood home is roughly the lawn in front of City Hall.

Most of the saloons and dance halls along South Rampart Street that gave birth to jazz in the first decade of the 20th century were demolished in favor of parking lots.

“There are precious few structures still standing today that document the powerful explosion of creativity and innovation that became jazz,” said John Hasse, curator of American music at the National Museum of American History.

Bolden’s house is one of them.

Bolden’s family rented the shotgun double on First Street in 1887, when he was 10.

Central City, in those days, was a working-class mix of German, Irish and African American families, like his. By accident of history it was home — or soon would be home — to a cluster of musical geniuses including, besides Bolden, jazz pioneers Kid Ory and King Oliver.

Music poured out of the place.

According to biographer Donald Marquis, Bolden’s home was just two blocks from the parade route favored by the Excelsior, Onward and other local bands. And down the street was Bolden’s own St. John the Fourth Baptist Church, whose ecstatic services and distinctive music also shaped his ear.

Musicians were everywhere.

Historians say Bolden was not the most technically proficient cornetist in town, but there is consensus on this: After other musicians heard him and his popular band, around 1900, they never played the same way again.

Bolden was doing something different, and it shifted the course of New Orleans music.

Marquis described it as the “extra touches” the untrained Bolden added by way of faking past passages he didn’t know. Bolden also added a distinctive new syncopated beat that opened room for improvisation. Others describe Bolden’s breakthrough contribution as his novel merger of blues, ragtime and street marches, influenced by church music as well.

Some experts disagree on whether he was playing jazz or a kind of proto-jazz brought to full flower by King Oliver and others.

To musician and jazz educator Wynton Marsalis it’s clear: “He played jazz. He’s the originator of jazz. He’s the progenitor.”

“All the music we play comes out of Bolden’s style,” Marsalis said. “His legacy is the history of jazz.”

Bolden’s career was dazzling but brief, lasting less than a decade. He fell into the grip of schizophrenia at 29, collapsed during a parade in 1906 and was institutionalized for the rest of his life.

He was buried in a pauper’s field in New Orleans in 1931. No one knows exactly where. His fans erected a monument approximating the site in 1996.

“(Bolden) practiced in the house and on the front porch stoop in front of the house. If it were possible to pinpoint the birthplace of jazz, it would have to be here,” Marquis wrote in 1978, urging the city’s Historic District Landmarks Commission to grant the house landmark status.

Marquis and others were successful, and today the commission watches over the house as a designated landmark.

City Hall records show that in 2011 and in January 2014 Greater St. Stephen was cited for allowing the house to deteriorate. A $575 fine accompanied the second violation.

In each case, the church made the mandated repairs.

“I’m not fearful for these particular properties, in that they seem to be being maintained in a watertight condition,” said Elliott Perkins, the commission’s executive director.

“We’ve gotten them to the minimum standard. I do worry for them in a long term way. But I don’t think they’re in immediate danger.”

But many people remain anxious.

Jack Stewart, a contractor and jazz lover who, years ago, rescued Jelly Roll Morton’s deteriorating house, pointed out that vacant houses are inherently vulnerable to slow, unseen threats like termites and water damage and to sudden calamities like fires set by vagrants.

In 2011, the Louisiana Landmarks Society named the Bolden house as one of the nine most endangered properties in the city. (The group nominates nine different historic properties every year.)

And the nonprofit Preservation Resource Center is anxious to get the vacant house back into use.

“The Bolden house is one of our top priorities at this point,” said Michelle Kimball, a senior advocate for the center.

In earlier cases, the PRC purchased the endangered homes of jazz pioneers Kid Ory and Red Allen, renovated them and sold them back to individuals. They are safe today, but such a purchase is not in the cards for the Bolden house, Kimball said.

Kimball said her organization tried to match the church with a willing buyer, but Greater St. Stephen’s spokeswoman Young confirmed the church was not interested in selling because it now has its own revitalization plans.

Young said Greater St. Stephen’s purchased the house to use in its ministries, not knowing its past or realizing it had landmark protection.

Three months later, a fire ruined its Central City church, a block away. The church building remains vacant, and the congregation now meets far away in eastern New Orleans.

Greater St. Stephen’s is in the midst of a capital campaign to reclaim the empty church and its surrounding properties, including the Bolden house, Young said.

“We plan to bring the Bolden house back into commerce, and we are exploring how to document the influence of spiritual music and the music of Buddy Bolden’s day,” she said. “We want to honor it. And we’re going to do it by doing more than putting a plaque on the home.”

Young said church representatives have scheduled a meeting with Marsalis in May to talk over preservation ideas.

Mora Beauchamp-Byrd, the interim executive director of the African-American Museum of Art and Culture, said she is exploring plans for the Bolden house on behalf of the church.

“We don’t need anybody to save the day,” Young said. “We’re going to pay homage to Buddy Bolden, an African American-musician, and we’re going to do it properly.”