The old “let’s put on a show” plot gets the animated treatment in “Sing,” Garth Jennings’ amiable, fast-moving jukebox musical with a playlist adults will enjoy and enough cheerily colorful critter shenanigans to keep the kids happy.

Matthew McConaughey voices Buster Moon, a high-energy koala who’s had the theatre in his blood ever since he was a tyke. He invests his inheritance in a music hall where he serves as an enthusiastic MC, but all his productions have been bombs, and as his long-time secretary, sweetly doddering iguana Mrs. Crawly (Jennings himself), impresses upon him, his creditors—especially banker Judith (Rhea Perlman), a llama—are about to pounce. His big idea to save the place is to stage an amateur singing contest with a thousand dollars—his last cash—going to the winner. Unfortunately, in printing up the advertisements Crawly announces the prize at a hundred times that. No wonder the applicants stretch around the block and beyond.

The plot runs along two tracks. One involves Buster trying to keep one step ahead of his creditors and trying desperately to raise money—an effort that leads him to a legendary star, imperious Nana Noodleman (voiced by Jennifer Hudson and Jennifer Saunders), who just happens to be the grandmother of his layabout sheep buddy Eddie (John C. Reilly).

That material is amusing enough, since McConaughey brings spark to his would-be impresario and Reilly is, as usual, delightfully laid-back. (The two have an irresistible moment when they partner up at a particularly low point in a car-washing business.) But the real center of the movie rests with the group of contestants chosen by Buster from the multitude of applicants after a chain of goofy auditions (a cheekily droll montage)—each with as much of an obstacle to overcome as Moon. One is mouse Mike (Seth MacFarlane), an arrogant Frank Sinatra-type crooner being pursued by a bunch of gamblers out for revenge. Another is Ash (Scarlett Johansson), a porcupine whose punk boyfriend (Beck Bennett) dumps her when she takes a more popular bent and writes her own material. Then there’s Rosita (Reese Witherspoon), a homebody pig with a workaholic husband (Nick Offerman) and twenty-five high-spirited kids whom Buster teams up with hog Gunther (Nick Kroll), a garrulous, ostentatious dancer, and Johnny (Taron Egerton), a Cockney gorilla with a smooth voice but a mobster father, Big Daddy (Peter Serafinowicz), who wants his son to be in his gang. Finally there’s Meena (Tori Kelly), an elephant with a great voice but a seemingly insurmountable case of stage fright, who becomes a stagehand instead.

Despite the difficulties, Buster manages to mount his show, but in the effort to make it spectacular he sets the stage for a disaster that threatens everything, even his theater. Of course though he seems to be down and out, his dream will rise from the ashes in a toe-tapping finale in which each of his would-be stars will have his or her moment to shine.

“Sing” isn’t the most imaginative animated film released this year—it doesn’t even have the level of wit found in Illumination Entertainment’s “The Secret Life of Pets”—but its very familiarity is rather comforting, and it should have appeal across the age spectrum (although, given the abundance of established pop tunes on the soundtrack—though many admittedly appear only in brief snatches—it might actually work better for adults than kids). Certainly most older viewers will be impressed, if not necessarily surprised, at how well folks like Witherspoon, Johansson and Egerton handle the vocal requirements. (Hudson, Kelly and MacFarlane are, of course, better-known quantities in that respect.) Jennings’ British background, incidentally, definitely shows up in the characterization of Big Daddy’s gang, which—accents at all—suggests a spoof of English gangster movies associated with people like Guy Ritchie and Jason Statham.

All told, “Sing” may not hit the highest note among recent animated movies, but it’s an agreeably modern twist on an old formula.