It’s only a matter of time before someone in “Big Fish” inevitably refers to the protagonist of the piece — a larger-than-life spinner of tall tales from a quaint little Alabama town — as the proverbial “big fish in a small pond.”

The same could probably be said about the terrific Travis Smith, who assumes the role in artistic director Tom Key's Theatrical Outfit production, a splashy musical based on the novel by Daniel Wallace (and Tim Burton's film version of it). Although there's nothing exactly undersized about it in terms of its scale or scope, Smith's crafty performance, while not quite the whole show, is surely its catchiest attribute.

The script (by John August) spans many years in the life of Edward Bloom, and largely focuses on the conflicted relationship with his son, Will (played here by Ben Thorpe as a grown-up and Gabriel Bowles as a kid). In the movie, Albert Finney and Ewan McGregor portrayed the older and younger incarnations of Edward, but it’s to Smith’s boundless credit that he single-handedly portrays the character so fully and believably, from cocky high-school student to feisty senior citizen.

Along the way, Edward frequently regales Will with stories about his fantastical exploits, including encounters with a fortune-telling witch (Randi Garza), a kissing mermaid (Caroline Arapoglou), a misunderstood giant (Blake Burgess) and a circus showman/werewolf (William S. Murphey) — in addition to highly romanticized recollections about how he met the boy’s mother and found his true love (Laura Floyd).

Over time, Will grows weary of hearing so many “crazy, implausible” tales. Whether he’s a realist or a pessimist is open to debate, and likewise whether Edward is fulfilling a “glorious destiny” or shirking his “ordinary life” by “choosing fantasy” rather than “facing facts.”

A lot of the magical elements that are so intrinsic to “Big Fish” are decidedly harder to capture and convey in a theatrical setting — unlike a book (which can devote innumerable pages to descriptive exposition, if not simply leaving things to the reader’s imagination) or a movie (which can rely on computerized special effects to visualize events).

Key’s staging is fairly evocative, under the circumstances, with the notable exception of a sequence involving a flood. On the other hand, in one of the show’s more memorable musical moments (Floyd’s “I Don’t Need a Roof”), he actually incorporates rain into the scene.

In another (Smith and Floyd’s “Daffodils”), flower petals drift down from above the stage, to lovely effect. For a few of the bigger group numbers, however, it’s an awkward distraction to have Floyd, Thorpe and Julissa Sabino (as Will’s pregnant wife) stepping out of character to help fill in the chorus.

The generally pleasing score is by Andrew Lippa, performed under the splendid music direction of S. Renee Clark, leading a six-piece band. Among other song highlights: Smith and Floyd’s “Time Stops,” Smith and Bowles’ “Fight the Dragons” and — perhaps most aptly of all — Smith’s “Be the Hero.”

In more ways than one, it seems, he saves the day.

THEATER REVIEW

“Big Fish”

Grade: B

Through Dec. 18. 7:30 p.m. Wednesdays-Saturdays; 2:30 p.m. Saturdays-Sundays. $22-$48. The Balzer Theater at Herren's, 84 Luckie St., Atlanta. 678-528-1500, www.theatricaloutfit.org.

Bottom line: A fairly good show, an even better showcase for Travis Smith.