Magical Movie Ad-Libs.

• Author: GEHRING, WES

In 10 notable films, an improvisation added unexpected spice to the script.

LIKE MOST FILM FANS, I have always been fascinated with famous movie lines and the stories behind hem. For instance, Hollywood's censorship board originally wanted Clark Gable's Rhett Butler to exit "Gone With the Wind" (1939) by saying, "Frankly, my dear, I don't give a darn," instead of the then-taboo "damn." (Gee, that would really have sounded angry.) Did you know that John Wayne's often repeated observation, "That'll be the day"--as director John Ford's most darkly ambiguous character, Ethan Edwards in "The Searchers"(1956)--was the inspiration for a pioneering rock `n' roll classic? Texas-born Buddy Holly so enjoyed both this watershed western and the expression that he wrote and recorded the hit song, "That'll Be the Day."

As a student of comedy, however, my fascination with the story behind memorable lines has been piqued most often by improvised lines--gems which are hatched at the last minute, usually by an ad-libbing actor. Improvisation is not limited to comedic situations, though it is most associated with laughter. Appropriately, the majority of the following examples (a personal pantheon of 10, arranged chronologically) are funny in nature.

The first is from the much-praised, archetypal screwball comedy, "Bringing Up Baby" (1938). Directed by the celebrated Howard Hawks and starting Cary Grant and Katharine Hepburn, it was part of a genre in which improvisation was often encouraged. The setting for the quip is the Connecticut forest where the two stars go in search of title character Baby, a runaway tame leopard.

In this slapstick outing, which involved plenty of Hawksian physical comedy (including falling down an incline and swimming a stream), Hepburn manages to lose part of a shoe. Without breaking character, she ad-libs with comic enthusiasm: "Oh, look, David [Grant], I've lost my heel. I've lost my heel. Look at me walk. [Laughing, she begins to walk in a comically exaggerated up-down motion.] I was born on the side of a hill. I was born on the side of a hill."

This fittingly funny observation, coupled with Hepburn's own comic choreography (the up-down walking movement), easily makes this one of the movie's most charming moments. Hawks was able to capture it on film because all of the talent on his pictures, both on-screen and off-, were instructed to work through a scene regardless of whatever script variations might occur while the cameras were rolling.

The second spotlighted line is from the timeless "The Wizard of Oz" (1939). Because this was an expensive, high-profile production by MGM (the Hollywood studio least receptive to unscripted material), director Victor Fleming could hardly encourage ad-libbing. Nevertheless, with a cast of witty former vaudevillians, an off-the-cuff comment was bound to stick, and one came courtesy of Bert Lahr.

The setting is the poppy field just outside the Emerald City. Thanks to the wicked witch (Margaret Hamilton), the poppies have cast a sleeping spell on Dorothy (Judy Garland) and the Cowardly Lion (Lahr). While the Scarecrow (Ray Bolger) and the Tinman (Jack Haley) cannot muse the two, good witch Glinda (Billie Burke) comes to the rescue with some modest snow flurries. Presto!, Dorothy and the Cowardly Lion are revived by this summer storm. Awakening from his snooze, Lahr gifts viewers with an inspired ad-lib: "Unusual weather we're having, isn't it." It is the perfect matter-of-fact topper to Glinda's ethereal release.

The next impromptu dialogue comes from director Carol Reed's "The Third Man" (1949), which the British Film Institute recently selected as its cinema's greatest picture. The scene is a post-World War II amusement park in Vienna, and Orson Welles' title character, the mysterious Harry Lime, is concluding a meeting with onetime friend Holly Martins...