There are many things that make "It's a Wonderful Life" an enduring movie classic: the amiable good humor, the sweet-but-not-saccharine love story, the perfect mixture of drama, desperation and heavenly intervention. All these make a viewing of Frank Capra's masterpiece a holiday tradition. But if you're like most people, you ask yourself: Why isn't there more singing? (OK, there is some: Jimmy Stewart and Donna Reed struggle through a few bars of "Buffalo Gals" near the beginning, and there's a rousing chorus of "Auld Lang Syne" at the end. But that's about it.) Well, fret no more. This year, turn off the TV and go to the theater for your "Wonderful Life." Sheldon Harnick and Joe Raposo, two show-biz vets, have collaborated on a theatrical adaptation of the movie (shortened to just "A Wonderful Life") that TheatreVirginia is featuring this holiday season. Harnick, lyricist for such blockbusters as "Fiddler on the Roof," wrote the show's book and lyrics. Raposo, a Grammy award-winning songsmith responsible for "Sesame Street" classics like "(It's Not Easy) Bein' Green," contributed the music. Together they expand important turning points in the story into songs: evil Mr. Potter's seduction of the frustrated George Bailey becomes "First Class All the Way;" the intervention of the Depression into George's honeymoon plans is captured in "Panic at the Building and Loan." Still, why should anyone pay several times more than it would cost to rent the video to get dressed up and go to the theater? "When you take the magical moments in the film," says "Life's" director William Wesbrooks, "and add music to them and make it a live experience in a theatre, you have basically increased that magic a thousand fold." It also stands to reason that it'll be easier to identify with George Bailey as just your average good-hearted schmo in the stage version. Instead of being played by a big-time movie star, at TVa the role of George went to real-life good-hearted local boy Duke Lafoon. Each version has its charms. But it's impossible to truly compare stage to screen. As Wesbrooks says, "It's an apples-and-oranges kind of thing."