On Tuesday, the Keswick Theatre in Glenside hosts an event that, at first glance, might seem like a mismatch, even bizarre.

Jazz trumpet master Wynton Marsalis and a 10-piece ensemble will be accompanying - a silent film.

Yet that silent film is new, not old, and so are events like this, at which musical masters play live to accompany silent movies.

The film in question is Louis, directed by Dan Pritzker and shot by Oscar-winning cinematographer Vilmos Zsigmond (Close Encounters of the Third Kind). It's less of a biopic than a riff on the life of Louis Armstrong.

Marsalis' group, featuring Victor Goines, Ted Nash, and other stalwarts of the Lincoln Center Jazz Orchestra, will play original pieces along with classic works by Jelly Roll Morton and Duke Ellington. Philadelphia is the last stop on a tour that includes Chicago, Detroit, Washington, and New York's Apollo Theater.

One paradox of silent film is that it has almost always involved the sound of music. Musicians - mainly pianists - once worked in movie houses as live accompanists, providing sound tracks in real time.

In recent years, jazz players as diverse as Wycliffe Gordon, Bill Frisell, Dave Douglas, Louis Sclavis, and the late Willem Breuker have helped revive the art of silent film accompaniment, shining new light on the antics of Fatty Arbuckle and Buster Keaton or the darker visions of directors such as Oscar Micheaux and F.W. Murnau.

Pianist Cecile Licad will also perform the melodic, florid, technically demanding music of 19th-century American composer Louis Moreau Gottschalk. Throughout the film, the solo piano and jazz ensemble segments are seamlessly juxtaposed, a contrast as odd as it is logical. You could call it a battle of the bands.

Pritzker, formerly a guitarist and songwriter with the Chicago-based rhythm-and-blues band Sonia Dada, sets Louis in 1907 New Orleans, using Armstrong's boyhood as a backdrop for a storyline he describes as "operatic, melodramatic, in the way that a lot of silent films are."

We get the stock characters: damsel in distress, mustache-twirling villains, and an unlikely, chubby-cheeked hero who saves the day - the young Louis, portrayed by Anthony Coleman, not to be confused with the jazz pianist of the same name.

In a fantasy sequence owing more than a little to Charlie Chaplin's Modern Times, the corrupt Judge Leander Perry (played by Jackie Earle Haley, of A Nightmare on Elm Street and Little Children) cavorts inside a set of mechanical gears. But the reference is also fairly current: The gears are part of a Diebold voting machine the judge has rigged. There's even a reference to hanging chads, evoking Gore v. Bush in 2000.

Pritzker and Zsigmond gave the movie an antique feel by shooting in color but desaturating the footage. The result is "not a sepia, not an indigo," Pritzker explains, but rather an alluring, curiously faded patina.

They enhanced this by shooting at 18 frames per second instead of the standard 24. "When you play it back at 24," Pritzker continues, "you get that sort of staccato feel, that slightly faster speed," an approximation of the hand-cranked camera techniques of old.

"The rest of it is very modern," Pritzker observes. "Our moving camera, the lighting, the huge crane shot into the cemetery - that's all modern filmmaking stuff."

In the music, too, we hear a fruitful tension between the vintage and the contemporary. Marsalis alters Ellington's 1927 "Black and Tan Fantasy" with a descending bass line from "Portrait of Wellman Braud," a movement from New Orleans Suite, which Ellington recorded in 1970, near the end of his life.

Elsewhere, snippets of the band playing "Boogie Stop Shuffle" and "The Black Saint and the Sinner Lady," by Charles Mingus, animate a climactic chase scene.

Gottschalk's piano music, with its Lisztian romantic flourishes, somehow meshes readily with the world of Jelly Roll Morton and other early jazz figures. Born in 1829 in New Orleans and dead by age 40, Gottschalk - the film's other "Louis," if you will - incorporated Creole and Caribbean influences into a rich regional sound of his own. "To me," Pritzker says, "there's a direct line from Gottschalk to Scott Joplin to Morton. Contained in there is a landscape of American music."

Pritzker considers Licad the best Gottschalk interpreter, more attentive than most to dynamic variation.

"It's very upbeat and fun," Licad says of Gottschalk's music. "The way the rhythm flows, it has a certain swing in it."

It so happens that Licad's great-uncle, the Filipino composer Francisco Buencamino, made a living as a silent film accompanist. "My mother was very close to him," Licad recalls. "When I was a kid and working on music, my mother used to act things out, and so I always related music to acting, to telling a story somehow."

Louis is a companion piece to a full-length sound feature called Bolden! that Pritzker hopes to release in 2011 or early 2012. Inspired by the life of fabled New Orleans jazz innovator Buddy Bolden, it's "a much bigger, more complex film," Pritzker says. Essentially, both films were shot at once, with the same cast, crew and locations.

Anthony Mackie plays Bolden. Wendell Pierce, of Treme and The Wire fame, appears in the role of Bartley, a savvy promoter. Marsalis will again provide the music.

Little is known about Bolden; nearly everything is known about Armstrong, "down to the socks he wore," notes Pritzker. But the aim was to portray both Armstrong and Bolden through a mythical lens.

"I was absolutely not interested in doing a biopic," he declares.

Instead, we get a fantasia on the roots of jazz and American culture. Louis is lighthearted, even a little fluffy, but Bolden! promises to make myth with more ambition.