Douglas Fairbanks will be up to his usual swashbuckling as the Fox Theatre screens the 1920 silent film classic "The Mark of Zorro" Thursday night, but theater organist Clark Wilson will be performing his own act of derring-do on the "Mighty Mo" theater organ.

Everything was super-sized when William Fox opened the Atlanta link in his movie palace chain in 1929, so it was fitting that the M.P. Möller Company was commissioned to produce its largest instrument for the Moorish-styled attraction.

One of most prominent scorers of silent films and a busy concert organist, Wilson says Mighty Mo's expansive, horseshoe-shaped console is "always a challenge to get back on top of." The gilded console itself is 58 inches long by 35 inches high by 26 inches deep, and the organ's overall dimensions are roughly double those.

Small wonder since it contains the keys to a world of musical feats. It can create the sound of instruments from a glockenspiel to a concert piano (a real one, remotely played from the organ's keyboard) and produce sound effects from tower bells to thunder claps.

Mighty Mo is the second-largest theater organ in the world, after Radio City Music Hall's, with 42 ranks (individual sets or rows of pipes operated by a single control), four manuals (keyboards) and 376 stop tabs. It boasts 3,622 pipes spread out over five chambers, ranging in size from a ballpoint pen to 32 feet tall and wide enough for a man to stand inside.

"It’s always nice to have a few hours alone with the organ to get reacquainted," said Wilson, who is based in East Liverpool, Ohio, but travels 80 percent of the year to concertize as well as to repair or install organs. "Because in the scoring of the picture -- in this fast motion jumping from scene to scene and effect to effect -- you’ve got to be able to get around that organ console quickly. There's no time to pause and say, ‘Now, where is such and such?' You've got to be able to reach out fast and grab what you need."

Thursday's screening marks the second year that the American Theatre Organ Society and Turner Classic Movies have presented special silent film screenings as part of the Fox's Coca-Cola Summer Film Festival, a series dominated by recent Hollywood hits.

Wilson, who has created 45 scores for popular silent films, said that "Mark of Zorro's" original 1920 score of Spanish-influenced music and rhythm still exists and he's heard it, though he's never read it. He prefers to play his own score, which employs a lot of the same music, including compositions by Bizet and Pierné.

To Wilson, there's an element of authenticity to using his own "cue sheets," which he defines "road maps of action" that are less detailed than a full score. In fact, many silent films did not come with scores and the ones that did often were ignored by theater organists in favor of cue sheets or improvisation.

"Bearing in mind that the theaters changed pictures three times a week and organists performed the show five times a day, they were mighty busy folks," Wilson said. "The chance to read 150 sheets of fresh music that had just come with the picture, keep an eye on the organ, keep an eye on the screen, get it all coordinated and right, was pretty slim."

Every silent picture had and has its unique demands for the accompanist and Wilson said he finds "Mark of Zorro" to be a special challenge. It's a classic swashbuckler, sure, filled with sword fights and horseback chases, but it doesn't stop there. It also has a love theme running through it and comedic elements as well.

As a hybrid, the film "was blazing new territory," Wilson said. "It’s somewhat of a roller coaster of emotions and a roller coaster of actions."

Touring the country, he's played pipe organs in venues ranging from Organ Stop Pizza in Mesa, Ariz., (home of the world's largest Wurlitzer) to the Walt Disney Concert Hall in Los Angeles. He considers the Mighty Mo, on which he helped premiere a restored version of Fritz Lang's 1927 "Metropolis" in 2004, among his favorites.

"The scope of the instrument is so magnificent," Wilson said. "It can whisper, it can roar, shake the building and do anything in between. It’s a very famous instrument at a very famous theater. It’s certainly one of the top venues in our business to appear at."

FILM PREVIEW

"The Mark of Zorro"

Featuring theater organist Clark Wilson, emceed by Turner Classic Movies host Ben Mankiewicz. 7:30 Thursday $8, available at Fox Theatre box office and Ticketmaster outlets. Fox Theatre, 660 Peachtree St., Atlanta. 1-800-745-3000, www.ticketmaster.com.

Recalling movie palaces with music

For more on Atlanta's movie palaces from the 1920s through the 1940s and their organs, Callanwolde Fine Arts Center and the Atlanta Chapter of the American Theatre Organ Society will present the presentation "Pipes on Peachtree" at 3 p.m. Sept. 11. Speakers will include organ technician and historian John Tanner and Joe Patten, the Fox Theatre’s retired technical director who painstakingly restored the Mighty Mo organ in 1963 after years of neglect. Callanwolde’s 60-rank Aeolian residence pipe organ will be played before and after the program and the 1920’s Gothic-Tudor structure, a former Candler family mansion, will be open for touring. 980 Briarcliff Road N.E., Atlanta. $10 advance purchase online at www.ticketleap.com; $12 door (cash only). 404-872-5338, www.callanwolde.org. HOWARD POUSNER