The comical, incredibly tuneful “Legally Blonde: The Musical,” adapted in 2007 from the 2001 film of the same name by librettist Heather Hach and songwriters Laurence O’Keefe (“Bat Boy: The Musical”) and Nell Benjamin, opens Friday at Playhouse South in Kettering.

Katie McCarthy, who recently appeared in Playhouse South’s production of “A Little Princess,” stars as perky Delta Nu fashionista Elle Woods, who embarks on a humorous yet touching journey of self-discovery after following her ex-boyfriend to Harvard Law School. The principal cast includes Brad Bishop as Professor Callahan, Josh Livecchi as Emmett Forest, Angie Thacker as Paulette, Brian Kester as Warner Huntington III, Megan Rademacher as Vivienne Kensington and Stephanie Dodge as Brooke Wyndham.

“Elle is more complex than she seems,” said McCarthy. “I think the easy way out would be to make her a stereotypical California sorority girl who just wants to get her MRS degree, but she has much more depth than that. She really evolves throughout the show and can’t go straight from being a Cali girl to a serious lawyer over the 15 minutes of intermission. Balancing Elle’s high energy without making her seem like a dumb blonde was probably the most challenging part of the process for me.”

Particularly drawn to the Act 1 finale, the infectiously uplifting “So Much Better,” McCarthy also deems Elle an inspirational character women and men can find relatable.

“Elle proves throughout the show that you really can do anything you put your mind to and work hard enough for and you don’t have to change who you are in the process.”

Director Jim Brown, whose Playhouse South credits include “Joseph and the Amazing Technicolor Dreamcoat” and “Back to the ‘80s,” has been very pleased with McCarthy’s magnetism in rehearsals. He feels confident in her ability to connect with the audience and remain appealing throughout.

“The script is 130 pages, and Katie is on stage for 125 of them,” Brown said. “For someone to be visible to the audience for such a substantial part of the script really requires a very happy presence like Katie. She’s providing an incredible balance of all the things you need to play Elle Woods. You need a subtle balance between poise without arrogance, being humorous instead of ditzy and an ability to be introspective without being too serious. I believe Katie has done a phenomenal job of capturing these moments. I think it’s going to be an amazing production just to watch her interpretation of Elle alone.”

Brown’s collaborators include choreographer Greg Andrews, musical director Brett Greenwood (who also served as musical director for Playhouse South’s excellent “Children of Eden” earlier this year), pianist Nancy Perrin (who recently provided fantastic accompaniment for Dayton Playhouse’s “Side by Side by Sondheim”) and scenic designer Ray Zupp.

“Regardless of what kind of theatergoer you are, you just want to be entertained,” said Brown. “ ‘Legally Blonde’ has a very entertaining script and is a very entertaining show. It has a good balance of humor while still having a message. If you’re looking for a good time, you’ll enjoy this show and perhaps take a bit of wisdom along the way.”

“I really just want people to have fun when they’re watching the show,” McCarthy said. “It’s such a lighthearted and happy production.”