What's this — the matriarch of the Partridge family in bed with a 24-year-old stud? It happens in "Grandma's Boy," a boisterous comedy produced by Adam Sandler's company.

"It's a different role for me," laughs Shirley Jones, the star of "Oklahoma!," "Carousel," "Music Man" and other squeaky-clean movies.

"People ask me, 'Why would you want to do a role like this?' I say, `Look, I've been Mrs. Partridge for many years. Let's face it: I won an Academy Award for playing a prostitute in 'Elmer Gantry.' This is the kind of role that at my age (71) it's fun to play."

The fun starts, she related, when three housemates — played by herself, Shirley Knight and Doris Roberts — find a jar left in the kitchen by a previous tenant. The contents look like tea, so they heat up a brew. What they're actually sipping is hashish. That's when things get wild with a group of fun-loving young men.

A possible antidote to "Grandma's Boy," which opens this weekend, could be "Hidden Places," which airs on the Hallmark Channel on Jan. 28 at 9 p.m. Being a Hallmark production, it's gotta have heart and nothing to upset the family.

So appropriately enough, Jones plays an old lady with glasses, long gray wig and men's clothes who has been banished to a back bedroom by her Depression-era farm family. When the father dies, his daughter and two children face losing the farm. Aunt Betty, called Aunt Batty by her relatives, comes to the rescue.

From horny grandma to goofy aunt in the same month — just another chapter in an amazing, unending career that has seen every form of show business except the circus.

But who knows — that could be next.

Shirley Jones lives in a rambling, hillside house in suburban Encino with her husband and manager, former comic Marty Ingels, and three dogs.

The pets bark noisily at an arriving visitor, then turn downright friendly. When the noise dies down, Jones settles onto a soft divan for an interview. She'll be 72 on March 31 but shows little evidence of her calendar age except for the snow-white hair, close-cut with stylish bangs.

She demonstrated her resilience last summer when she starred on Broadway in "42nd Street," playing opposite her son Patrick Cassidy. "I hadn't done a show in 38 years, and I had four songs and five costume changes," she remarked. "I'm no kid, and I said to Patrick, `I'm not sure I can make 8-9 shows a week. I'm not sure I can sing that much, even though I'm still doing concerts.' Patrick said, `I'll take care of you,' and he did."

Jones started her career in her hometown of Smithton, Pa., where at age 6 she was the youngest member of the church choir. She played leads in high school musicals and appeared summers at the Pittsburgh Playhouse. She won the beauty contest for Miss Pittsburgh and barely missed becoming Miss Pennsylvania.

In the summer of 1953, on her way to college with plans for a veterinarian degree, something "incredible" happened.

"I was 17, and I went to an open audition for Rodgers and Hammerstein, who had three shows on Broadway and needed replacements," she recalled. "I sang for the casting director, and he asked me what I had done, and I said nothing, really. He said Richard Rodgers was across the street, and he'd like Mr. Rodgers to hear me personally."

Rodgers liked what he heard, and he sent for Oscar Hammerstein. By this time the accompanist had left, and the pair took Jones across the street to sing with the City Center Symphony, which was preparing for another company of "Oklahoma!" The girl, who had never heard a symphony orchestra, much less sing with one, did three songs from the show and was offered a contract and a role in the long-running "South Pacific."

"I thought I should go on to college," she said, "but my parents told me, `This might be the chance of a lifetime; you can always go to college.'"

After six months with a minor role in "South Pacific," Jones learned R&H had a grander plan for her: the female lead in the movie version of "Oklahoma!" She did well in an audition but was considered too young and inexperienced.

She was assigned the lead of another R&H show, "Me and Juliet." After six months, during which scores of girls tried out for the role of "Oklahoma's" Laurie, Jones was brought back to the production, sailed through a screen test and was chosen for the part.

She followed with the film version of "Carousel" and "April Love," a youth musical with Pat Boone. Then Hollywood stopped making musicals; they performed well in the U.S. but bombed in the all-important European market.

Jones turned to drama, stunning the film trade with her 1960 performance for "Elmer Gantry." Later, she turned to television, where she was embraced by a whole new generation of fans as the mother of "The Partridge Family" (1970-1974), in which she starred with her stepson, David Cassidy.

She has pleasant memories of the series and keeps in touch with most of her "family." "It was a wonderful almost five years," she said glowingly. "I got to stay home, raise my kids." She has three sons from her marriage to Broadway singer Jack Cassidy, and now she has seven grandchildren.

Shirley Jones gives no sign of quitting. She is booked for four concerts in early 2006, some with symphony orchestras, some with piano accompaniment and clips of her movies. She has regular sessions with a voice coach and pedals several miles daily on her stationary bicycle.

"I lost 14 pounds doing `42nd Street,'" she commented, "and I swore I would keep them off. And I have."