FORT WORTH — Youd have to be one heck of a Grinch to find too many reasons to dog on Dr. Seuss How the Grinch Stole Christmas: The Musical, which opened Tuesday at Bass Hall for a weeks run, presented by Performing Arts Fort Worth.For those of a certain age, this oft-amended musical staging is a far cry from the beloved 1966 television special based on Theodore Geisels funny/sweet satire of over-commercialization of Christmas. But its worlds better than the ill-advised live-action movie starring Jim Carrey.With a book and lyrics by Timothy Mason and music by Mel Marvin (with additional music by Albert Hague and Dr. Seuss, meaning they use songs from the 1966 TV special, notably Youre a Mean One, Mr. Grinch), the story has been expanded from childrens book-length (the TV special was 30 minutes) to 90 intermission-less minutes. This stage version, originally conceived and directed by Jack OBrien and directed in the current touring version by Matt August, has been toyed with at various regional theaters since the 1990s, and first appeared on Broadway in 2006.The biggest way it strains to extend the time so that you feel you got your moneys worth (and at these fancy halls, thats quite a few greenbacks) is to spend last 30 minutes reprising six of the shows 10 songs one of them twice (there had already been one reprise earlier in the show). After about an hour, the welcome feels worn out and, on Tuesday night, several parents bailed, carrying their sleeping little ones in their arms.But there is one very powerful weapon to keep children of all ages engaged, and its the title character, here played by Stefan Karl, who has been touring in the role for several years. In costume designer Robert Morgans hirsute green suit, complete with ungodly long fingernails, Karl has the mean-spiritedness, fussiness and sarcasm of the character perfected. He keeps the young kids laughing and screaming with delight, and scores extra points for updated gags, like use of the word hashtag.Cindy-Lou Who, the young girl in Whoville who ultimately wins the Grinchs heart and saves Christmas, is adorably played by Piper Birney, alternating with Jenna Iacono. When she launches into the shows most saccharine song, Santa for a Day, its awwww-inspiring and the Grinch is in on the joke, announcing, Oh, its the ballad. Big laughs.The Grinchs unloved shaggy dog is played as a young pup by Andreas Wyder and as Old Max, who serves as narrator, by Bob Lauder. Both hit the right strides. Morgans costumes and John Lee Beattys set recreate the original illustrations in the book and capture the spirit of Chuck Jones animation on TV.Adults may wish for a few more winks to them, but this musical unapologetically plays to its target audience of young uns. It would take a real mean one adult, that is to suggest that this tactic doesnt work. Judging from the laughter and smiles from the kids in the audience, it works just fine.