Three seems to be the magic number for Encore Theatre’s new production of Andrew Lloyd Webber and Tim Rice’s “Joseph and the Amazing Technicolor Dreamcoat.”

For not only does the production have three rotating casts of kids—which means that each musical number involving them must be done three times at rehearsal—but the show’s narrator will be played at each performance by the three members (Madison Deadman, Megan Casey, and Bryana Dorfman) of a local pop/country group called Sir3n.

Encore co-founder Dan Cooney and associate artistic director Thalia Schramm approached director Barbara F. Cullen with the idea to cast Sir3n in "Joseph," inspired partly by Deadman’s (“The Sound of Music,” “Nunsense,” “Little Women”) and Dorfman’s (“Annie”) previous work in Encore productions.

“(Cullen and Schramm) came to me and said, ‘What do you think?” and I said, ‘What a cool idea. Let’s go for it!’” said Cullen. “ … What I did was, all through November and December, I took the score, and I broke it down, deciding who sings what line, and what parts needed extra harmonies.” (Music director Jonathan Sills also contributed to this process.)

“Interestingly enough, when I looked at the score, I noticed that several times, like in ‘Jacob and Sons,’ a line is repeated three times, so it seemed immediately perfect,” said Cullen. “ … It made me see the show in a whole new light.”

Telling the biblical story of Joseph—a young man who could interpret dreams, but who also was the favorite of Jacob’s 12 sons—the show follows Joseph as his jealous brothers sell him into slavery.

The show was written for a children’s choir, and was first presented as a 15-minute pop cantata in London in 1968, before being released as a full-length concept album in 1969. It wasn’t presented on stage until 1970 (after Webber and Rice struck gold with “Jesus Christ Superstar”) and premiered on Broadway in 1982.

“The first production that I ever saw of this show was very basic,” said Cullen. “Not a lot of movement or choreography. But it has grown through the years, and the arrangements have also grown. Then Donny Osmond did it (beginning in 1992 in Toronto), and it became much more popular as a theatrical piece, and had much more choreography. “

The show’s goofy sense of humor is reflected in its eclectic score, which features calypso, Elvis-inspired rock and roll, country, French balladry, disco, and Charleston.

“The show’s appeal is that there’s something for everyone, as far as its style goes, musically, and that it moves so quickly,” said Cullen. “When I first did the show, not being from religious family, I had to study the Bible, and I’ve kept my notes, so that every time I do the show, I reread that section of Bible. And it amazes me how closely the show follows that section about Joseph and the dreamcoat. So I think, for people who are very religious and get into the Old Testament, it’s a fun way to tell the story. People who are not familiar with the Old Testament just think, ‘Wow, this is really fun.’”

As for the kids’ chorus, Cullen cast three rotating casts of six. “Because the space is small, I’ve incorporated the kids into the show,” she said. “It’s more fun for them, because they get to do more than just sit there. Usually the choir is sitting on the sides, on risers, but our kids are involved in the show itself, and become part of story.”

This may make the already-family-friendly show an even bigger draw for those with kids.

“(The young cast members) are doing great work,” said Cullen. “ … I think it really gets other kids excited about theater to see kids their own age up there (on stage) doing it, too.”

Jenn McKee is the entertainment digital journalist for AnnArbor.com. Reach her at jennmckee@annarbor.com or 734-623-2546, and follow her on Twitter @jennmckee.