Polyphony, angular harmonies and intricate melodies.

Those are the trademarks of America’s greatest musical-theater composer and lyricist, Stephen Sondheim.

In other words, singing a Sondheim musical takes chops, but if you can pull it off and challenge an audience to really listen, the magic spills off the stage.

Enter Susannah Rose “Rosie” Woods. She’s a veteran theater director recently of San Francisco who surveyed the field in Langley and liked what she saw.

Woods is deep into rehearsals of not just one, but two productions for Whidbey Children’s Theater of Sondheim’s Tony Award-winning “Into the Woods,” with musical direction by Kira Vogt.

A cast of local 9- to 13-year-old performers will present the junior version of the show with live musical accompaniment March 19 to 21.

What starts out as “happily ever after” in Act I ( the junior version) goes awry in Act II. The consequences of the most iconic fairytale characters’ actions return to haunt them with disastrous results. Ultimately though, like every fable, this story has a moral in the end.

A high-school-age cast of actors will perform the full Broadway version March 26 to April 3.

In this Broadway meets the Brothers Grimm, Sondheim and story author James Lapine weave together the tales of such characters as Cinderella, Little Red Riding Hood, Jack (and his beanstalk), Rapunzel and the witch.

“It’s a dark musical,” said director Woods, who has shown herself a consummate professional in being able to handle two casts at once.

How does one approach “Into the Woods,” with all its vocal shenanigans, and make it work?

“My mother calls Sondheim ‘he of the howling operatic cats,’” Woods said.

But for all its intricate dissonance in the score, handled deftly by both casts whom she praised for their talent, Woods said “Into the Woods” is musically satisfying. Eventually there is a clarity that comes out of discord which follows the through-line of the play’s characters.

“It’s like that piece in ‘Hamlet’ when he starts speaking in a strange rhythm and then returns to the rhythm of Shakespeare again,” she said.

Woods said that without the hard-working and joyful casts, such a challenging play would be impossible to stage.

“There’s these incredible kids and adults on the island who you only have to tell where to stand and pretty much they do the rest for you,” she added.

Woods also lauded her partner in craziness, musical director Vogt, whom she called “a force of nature.”

“She jumps into rehearsal and is willing to carve it up and dive into it. They all make me look great, which is what happens when you get out of their way and do your job well,” Woods said.

Although she is currently dreaming in counterpoint as the result of Sondheim’s tricky five- and six-part harmonies, often changing key several times within one song, Woods said she gains strength from the characters’ dilemmas; plays such as this that make people feel something.

“Things happen where people have to rally. In the end, a small group becomes a community. It’s very redemptive, that feeling of well, maybe yes I can do this,” she said.

And she did.

The cast of “Into the Woods” includes Trevor Hein, Justine Coomes, Andy Walker, Will Mellish, Gina Knox, Jasmine O’Brochta, Nicole Ledgerwood, Nicki Fjelsted, April Wilhelm, Carrie Walker, Allie Firth, Ambria Prosch, Erik Sundquist, Kim McLean, Kimmer Webb, Athena Michaelides, Savanna Seyler, Isabella Moreno, Talon Jorgenson, Ashlinn Prosch, Sarafina Durr and Colette Grove.

The orchestra is comprised of Lucy Rock, Siri Bardarson, Alec Buchanan, Zoe Hensler and Robert Marsanyi. The hard behind-the-stage work is done by Carrie Carpenter, costumes; Rod Stuart, technical director and Betty Lightner, props. Caitlin Goldbaum is the stage manager.

The cast of “Into the Woods, Jr.” includes Coel Cable, Meadow Holtby, Antonia Knox, Mariah Crawford, Libby Hawkins, Isadora Cass, Skye Maguire, Emily Anderson, Chloe Rose Dickerson, Emma Lungren, Nora Anastasi, Emma Anastasi, Alyssa Woodbury, Hannah Mack, Allison Lilly Graeser, Iona Rohan, Kayla Knauer, Tabatha Cass, Coel Cable, Alexandria Kurtz, Shady Moody, Miranda Cassee and Mackenna Kelly.

The junior-version crew includes lights and tech by Rod Stewart and Grace Stringer, set design by Rosie Woods, set creation by Jodi Cable, masks by Bill and Sam Cass and costumes by Carrie Carpenter. Julie McNeeley is the stage manager.

“Into the Woods, Jr.” plays at 7:30 p.m. Friday, March 19 and Saturday, March 20 and at 2 p.m. Sunday, March 21.

Parents please note: The junior version is more appropriate for younger children than the full version of “Into the Woods.”

“Into the Woods” with the high school cast plays at 7:30 p.m. Fridays and Saturdays, March 26 through April 3; and 2 p.m. Sunday, March 28.

Tickets are $12 for adults, and $8 for students and seniors. Family Night is at 7:30 p.m. Saturday, March 20, with all tickets $7. Call 221-2282 for tickets.

Whidbey Children’s Theater is at 222 Anthes Ave. in Langley.