Big Fish, opening Feb. 13 at the Martha’s Vineyard Regional High School, is a 21st-century musical inspired by the enduring tradition of heroic journeys.

“It doesn’t get more epic than this,” said director Brooke Ditchfield, during a break from rehearsing scenes at the performing arts center Monday afternoon. “It’s the Iliad, it’s the Odyssey. . . and then it’s Ulysses [by James Joyce].”

It’s also the largest and most ambitious musical Ms. Ditchfield has directed in her six seasons with the high school’s growing program. The cast alone numbers 47, playing some 100 roles.

“When we started six years ago, we barely got to 20,” she said.

An orchestra of more than a dozen musicians and a technical crew bring the Big Fish total to about 75 people, said stage manager Violet Cabot, a senior who’s been working on Ms. Ditchfield’s musicals ever since the director recruited her as a seventh-grader from West Tisbury.

This show will give Ms. Cabot and her crew more to do than any of the previous musicals, with props as small as fish and as large as a circus cannon, and a book full of tricky sound, lighting and transition cues.

Big Fish, the musical, is based on the 1998 book Big Fish: A Novel of Mythic Proportions by Daniel Wallace, and director Tim Burton’s 2003 film of the novel. Through a series of adventures that can only be called fabulous — confronting a giant, a witch and a mermaid, getting shot from a cannon and making fish fly, to name a few — protagonist Edward Bloom tells the story of his life to his skeptical, grown-up son.

The musical brings Edward’s tales to life with singing and dancing filling the stage with colorful action. Choreographed by Ken Romero, the dance scenes include a tap routine, a hoe-down and a calisthenic Alabama Stomp.

“I love how weird it is,” said Skylar Hall, who plays Edward. His son Will is played by Jaiden Edelman, who serves as Edward’s foil and antagonist. In one scene, feverishly dreamed by Edward as he sleeps, the two come face to face in an Old West showdown.

Ms. Ditchfield has double-cast the lead female role of Sandra, Edward’s wife and Will’s mother. Caitlin McHugh is playing the role on Thursday and Saturday, and Bella Giordano is Sandra on Friday and Sunday.

“I’ve never played a mother before, so it’s very different to have a love for somebody that is not romantic,” said Ms. Giordano, who shared the role of Rosalind in last year’s musical, As You Like It.

“Edward’s kind of out there and crazy,” while Will’s world view is more fact-based, said Ms. McHugh. “Sandra’s the one that pulls them together as a family.”

The Big Fish orchestra, led by performing arts department chair Abigail Chandler, is a mix of Island musicians, including MVRHS senior Tripp Hopkins on drums. The group is augmented by two professional string players from the mainland, one of whom plays in the touring production of Hamilton, Ms. Chandler said.

Chelsea McCarthy is designing the costumes, from sequined little tap-dance dresses to garments for the giant and his giantess wife. Like Ms. Cabot, Ms. McCarthy has worked on all of Ms. Ditchfield’s high school musicals, starting with Into the Woods in 2015. She gives Ms. Ditchfield full credit for the explosion of student interest in theatre over the past six years.

“She is an insanely amazing leader. She makes everyone want to work harder,” Ms. McCarthy said. “Everybody is warm and accepting and loving, and that’s because of Brooke.”

Mr. Romero, the choreographer, also praised the students’ enthusiasm.

“Everybody wants to be here,” he said.

Big Fish performances are Feb. 13, Feb. 14 and Feb. 15 at 7 p.m. and Feb. 16 at 2 p.m.