There’s nothing inherently wrong with somebody trying to profit off an ancestor’s legacy, which explains why one shouldn’t complain overmuch about Roger S. Baum’s decision to write a series of children’s books deriving from his great-grandfather Frank L.’s popular Oz volumes, even if you think—as some fans apparently do—that they’re poor substitutes for the real thing. “Legends of Oz: Dorothy’s Return” is a computer-animated adaptation of first of them, “Dorothy of Oz,” which dates from 1989. It’s safe to say that neither the 1939 classic nor even Walter Murch’s hugely inferior “Return to Oz” from 1985 (nor last year’s overblown “Oz the Great and Powerful”) need fear being overshadowed by it.

The plot has to do with Dorothy (voiced by Lea Michele), just returned from her original Oz adventure (though the backdrop appears to be much later than 1939), summoned back to Oz by the Scarecrow (Dan Aykroyd), the Lion (Jim Belushi) and the Tin Man (Kelsey Grammer) to help them defeat The Jester (Martin Short), the evil brother of the Wicked Witch of the West. He’s now in control of her powers, and is using them to turn all the major characters in the realm into marionettes, including good witch Glinda (Bernadette Peters).

Brought back to Oz via a rainbow transport, Dorothy (accompanied, of course, by Toto) joins forces with an unlikely bunch of helpers—Wiser the Owl (Oliver Platt), Marshal Mallow, a soldier of Candy Land (Hugh Dancy), and the China Princess (Megan Hilty)—to go to the Jester’s castle and save her friends. Though threatened by all manner of obstacles (including the Jester’s flying monkeys) as they pass through such provinces as Dainty China Kingdom and Candy Country on their way to the Munchkin River, they reach their destination, thanks to a boat they fashion from an elderly talking tree that, in his new incarnation, takes the name of Tugg (Patrick Stewart). An epic battle ensues between the forces of good and evil. There’s no prize for guessing which of the two wins.

Nor will any awards be forthcoming for the movie, which makes even Murch’s misfire seem laudable by comparison. The animation is basically mediocre, especially (as is often the case in these computer-generated efforts) in terms of the human characters—Dorothy (voiced by Lea Michele), of course, but also the people that appear in the wraparound Kansas scenes, like Aunt Em (Tracey Adams) and Uncle Henry (Michael Krawic), who are also a pretty dense bunch, open to being ripped off for the cyclone damage by an unscrupulous disaster appraiser (also voiced by Short). But even in the Oz wonderland, the characters never come across as magical in any respect, and the backgrounds are bland.

So too are the songs, for like the 1939 original, “Dorothy’s Return” is a musical, too. The problem is that you’re likely to come out of it whistling “Over the Rainbow” or any of the other classics from “The Wizard of Oz” than the instantly forgettable numbers featured here—a collection penned by a variety of hands, including singer Bryan Adams. Obviously the intent was to craft a Disneyesque playlist that might rival the soundtrack to “Frozen,” but the result resembles the score to a failed Broadway show rather than one that might wind up on the Great White Way after big-screen success.

Most of the starry voice talent is rather poorly used as well; the standouts are certainly Platt, who sounds like he’s actually having fun, and Stewart, who’s at least immediately recognizable. So is Short, but his manic delivery, even when he’s singing, is likely to grate more than gratify.

Very young children and extremely undemanding families might enjoy “Dorothy’s Return.” But mostly what it does is prove there’s no place like Victor Fleming’s Oz.