It used to be musicals started off on Broadway, then were adapted to the movies, but the modern pattern is the opposite: Non-musical movies become transformed into stage shows with singing and dancing. The issue is: What makes a good movie is not necessarily what makes for a good theatrical experience.

The 2003 Will Ferrell vehicle Elf is one such example. The film is a minor holiday classic, coasting mostly on the energy of its leading actor, as a human reared by Santa at the North Pole who, at age 30, finally ventures back to the U.S. It clocks in at about 90 minutes; the stage version, Elf the Musical, now at Fair Park Music Hall, is about an hour longer (including intermission). The exchange is a score of sprightly songs by Matthew Sklar and Chad Beguelin… and a number of not-so-memorable ones as well.

The plot is clever, but hardly innovative — our bright-eyed hero Buddy the Elf (Eric Williams onstage) exudes the Christmas spirit so lacking in hardened Noo Yawkuhs, including his biological father (John Adkinson) and the Macy’s seasonal worker (Paloma D’Auria) who Buddy takes a likin’ too. Complications (all predictable) ensue until all the Grinches become Hoovillagers.

There aren’t nearly enough jokes in the soggy script (surprisingly, by Tony winners Tom Meehan and Bob Martin), though a few of the songs are fun (especially the vamp “Nobody Cares About Santa”) and the elfin choreography (the actors are all on their knees… dancing). But like the film, it’s the energy of the lead upon which everything depends, and Williams pulls it off. His likability is infectious, and the middling musical benefits from it… and the kiddies won’t notice the major flaws.

— Arnold Wayne Jones

Through Sunday. DallasSummerMusicals.org.