Preservation Hall’s iron gates open to a hallway that leads to a single room. Built in 1750, the building has been left to age, plaster cracks unrepaired, windows unwashed. There’s no air-conditioning and almost no seats. No drinks. Just music: traditional New Orleans jazz.

When I saw a show there in 1994, after a long wait outside on St. Peter Street, my sister, who’s five feet two, could barely see the musicians through the tightly packed crowd. Each song was full of solos: the clarinetist, trumpeter, trombonist, pianist, banjoist, and drummer each improvised off the melody, creating an emotional crescendo that exploded in the final verse, where everyone pealed, drummed, and strummed through America’s most joyful style of music.

Most likely, though, we didn’t see the Preservation Hall Jazz Band, but some of a large cast of musicians who play early New Orleans jazz styles at the Hall while the house band tours the country — as it’s doing again this month.

The group was founded in 1961, when performances of early jazz at an art gallery became so popular that they displaced the gallery. The Hall’s purist focus on traditional music set it apart from other New Orleans clubs that expected musicians to compromise their art. Acclaim for the Hall and popular tours by the band quickly followed. The Columbia CD Best of Preservation Hall Jazz Band, recorded in the late 1970s and the 1980s, has become one of the most popular recordings of New Orleans-style jazz.

But the idea of preserving music unchanged is always partly illusion. Though Preservation Hall’s reverent musicians wouldn’t want to be associated with Dixieland’s straw-hat, striped-shirt clichés, their thrilling solo trading owed more to Dixieland revivals of traditional jazz than to the tight ensembles of 1920s-era New Orleans.

Time has transformed the band, now made up of a new generation of players. Their last recording, Shake That Thing (2001), was a mishmash that included jazzified dabbling in genres from Cajun to gospel. Musical director Ben Jaffe, thirty-five, son of cofounders Allan and Sandra Jaffe, has even led the band to reinterpret rock songs. It performed a slowed-down, swinging version of U2’s garage-rocky rave-up “Vertigo” with U2 guitarist The Edge at April’s forty-fifth-anniversary, post-Katrina reopening of Preservation Hall.

Five of the band’s seven core members lost their homes in the hurricane — but in concert, their music still chases the blues away. At the band’s May performance with the Cincinnati Pops, a Cincinnati Enquirer reviewer was moved by the solos — a drum intro, a trumpet line that got the crowd clapping. Only the band staple “Just a Closer Walk with Thee” struck the reviewer as resonating with the plight of New Orleans. But then John Brunious — whose curly white hair, wit, and leading role as trumpeter make him a center of stage attention — urged the crowd to dance, and the band roused them with the ultimate New Orleans song, “When the Saints Go Marching In.”

The Preservation Hall Jazz Band plays the Power Center as part of the Summer Festival Wednesday, June 21.

[Review published June 2006]