He has accompanied Paul Simon and Elvis Costello, Renee Fleming and Yo-Yo Ma, Brad Paisley and Emmylou Harris.

He is probably the most listened-to pianist in Minnesota, but most Minnesotans don’t know his name.

That’s because Richard Dworsky doesn’t exactly get top billing on radio’s “A Prairie Home Companion.” That would go, of course, to Garrison Keillor, but as the program’s musical director, Dworsky is almost as integral on every broadcast heard by 4 million listeners.

During the past 23 years, the piano man has accompanied those aforementioned famous guests and countless folk and bluegrass musicians you’ve probably never heard of.

Dworsky can play in any style with equal authority, which perhaps explains why his new album, “All in Due Time,” his first in 14 years, covers the gamut. There’s ragtime, bluegrass, hot jazz, classical, film music, Celtic folk, ballads, post-ragtime novelty instrumentals.

“I was trying to figure out who I was,” Dworsky said by his miked-up, ready-to-record Steinway in his Wayzata living room. “I’m all of that.”

No wonder Dworsky, 61, has been dubbed the Paul Shaffer of the prairie. Like David Letterman’s longtime bandleader, Dworsky is remarkably versatile, strikingly quick and, frankly, hair-impaired.

“Paul has been my idol,” said Dworsky, who said he wears a hat more to keep his body warm than to cover up his bald spot. “He came on the show, and we ended up playing a piano four-hands version of ‘Louie Louie.’ ”

Situated in the middle of the “Prairie Home” stage, hidden by his hat and headphones, Dworsky considers himself “blessed with a great job.” He has adapted several pieces from the radio show for his album.

“My compositional duties are a little bit like Bach writing a concerto every week,” said Dworsky, who seldom writes lyrics. “I come up with little pieces that can be used throughout the show. One style of composing I do is called improvising. It’s original music and original ideas, but they’re happening spontaneously, whether it’s under a silly comedic script or under one of Garrison’s monologues.”

Special guests on the album include dobro king Jerry Douglas and fiddler Stuart Duncan, two of Nashville’s top players, and Sally Dworsky, his Los Angeles-based sister, who has sung with Don Henley, R.E.M. and Peter Gabriel. She sings on “All the Joys (Lullaby for Lila),” which her brother wrote for her daughter 13 years ago.

One piece, “I Shall Not Live in Vain,” was an Emily Dickinson poem set to Dworsky music in the late 1970s. To sing it, he called upon seven-time Grammy winner Al Jarreau, with whom Dworsky played while in high school.

Jarreau’s teen accompanist

A child prodigy who was studying piano with a University of Minnesota professor at age 11, Dworsky was gigging in bands in downtown Minneapolis clubs as a teenager when he was recruited to accompany Jarreau in a duo. His two-month trip to Los Angeles lasted 2½ years, and his mother had to pick up his high school diploma in absentia.

Just before Jarreau landed his Warner Bros. recording deal, Dworsky left him to go study music at the University of Minnesota. He spent seven years at the Children’s Theatre Company as a pianist, conductor and composer and later recorded bestselling piano music for New Age-inclined Windham Hill Records.

It was Dworsky’s mother who helped get him on “Prairie Home.” Her late husband owned the complex that housed an apartment building and the World Theater. When she sold the property (to be renamed the Fitzgerald Theater) to Minnesota Public Radio and “A Prairie Home Companion,” she mentioned that her son was a versatile piano player. He got invited on the show and eventually became bandleader.

“Rich has everything,” Keillor said via e-mail. “He has classical training and classical skills, a solid foundation of theory, is a gifted and fearless improviser, and loves theater and performance. He’s a composer. He has a high harmony voice. He’s a gentle bandleader and a copacetic collaborator. He is a sensitive accompanist who knows how to be supportive but invisible. He’s the indispensable guy.”

For Dworsky, “Prairie Home” has been music grad school.

“In the ’70s, I had been with Al Jarreau trying to do hip jazz-rock,” said Dworsky, who said he’s classically trained by ear. “I knew nothing about bluegrass. I knew nothing about hymns. I knew nothing about roots rock, roots blues, roots jazz, the Celtic standards. That’s something I’ve learned on the job.”

Whether on the radio show or on tour with Keillor in his solo concerts and cruise-ship performances (where the pianist is an in-demand salsa dancer), Dworsky is ready for the boss to throw anything at him. It might be playing quietly while Keillor talks or improvising an instrumental to fill time (“The script just says ‘music’ ”). Either way, Dworsky jumps in with aplomb.

“That doesn’t scare me. Playing Rachmaninoff, now that scares me,” Dworsky said.

Uncertain future

The St. Paul-reared piano man is uncertain about when he’ll do an album-release concert for “All in Due Time” because he has “Prairie Home” commitments into July.

The radio show and performances by “Garrison Keillor and Friends” have kept him so busy that he can’t remember the last time he headlined a concert in the Twin Cities.

“It’s been forever,” he said. “I haven’t been promoting myself.”

If he were, he wouldn’t try a George Winston or Keith Jarrett solo-piano approach. “I’d do a concert like my CD — a music variety show with stellar collaborators,” he said.

But any solo career is on hold because his status with “Prairie Home” is uncertain. Keillor will retire as host this summer, and mandolinist extraordinaire Chris Thile will take over.

“Chris and I are great buddies and have a lot of mutual respect,” said Dworsky, who would like to continue on the show.

But the future?

“There’s nothing specific to announce,” said Dworsky, not sounding concerned.

Then he added: “I’ve never filled out a job application in my life.”