Pianist Butch Thompson is happy. He's so sanguine that, in the course of an hourlong telephone conversation, he said "happy," "glad" or "lucky" so many times that he almost sounded giddy.

The mustachioed Minnesota jazz institution is happy because he's going to return to the concert stage Saturday for the first time since February. He's glad because he's celebrating a new album with the Southside Aces. He's lucky (his word) and grateful (his wife's word) because he still gets to play piano for people even though he's dealing with two debilitating challenges: memory loss that he's been experiencing for four years and a hand disease, Dupuytren's contracture, that he's been fighting for 40 years.

"I'm managing to still play reasonably well," said Thompson, who turns 77 next month. "I've worked on it. I practice all the time. My brain isn't what it used to be. But when I sit down to play, I can actually do it. But the fingers have to get fixed all the time. It's a nuisance. I'm just lucky to be able to do it the way I'm doing it. I hope to keep doing it for a long time yet. I'm feeling good."

Like a New Orleans funeral parade, Thompson is decidedly upbeat under the circumstances.

Mary Ellen Niedenfuer, his wife of 28 years, says he's been doing better, especially since he had another hand surgery seven weeks ago.

The genetic condition, also known as Vikings disease, causes fingers to bend toward the palm. It tends to afflict men of northern European heritage, according to the Mayo Clinic. Thompson is half-Norwegian, half-Swedish. He does therapy three times a day, with lots of massage and stretching.

"It's what it is. But I'm dealing with it. I'm getting away with it and I enjoy it," Thompson said with a hearty chuckle. "I used to see a couple of guys in New Orleans that had something like what I've got. It's a long time before I actually had it myself. Their fingers would be in the way. Kid Thomas Valentine — he played trumpet — his fingers looked funny to me."

Because of the memory issues, the Southside Aces — a Twin Cities traditional jazz band with which Thompson has played for three years — no longer rely on the pianist to kick off numbers.

"As soon as we start, there must be a direct nerve that goes from his ears to his right hand because after he hears two notes, he hits the right note on the piano and everything floods in and he's playing with us," said clarinetist Tony Balluff, co-founder and leader of the Aces.

Despite the memory challenges, Thompson's personality hasn't changed.

"He's still really himself," his wife said. "He's such a kind, sweet person. I'm lucky he doesn't get mad and impatient. He's always been so Zen. He'd always take things in stride. Now he's at the point that he's really grateful."

Thompson realized the memory issues himself when his attention wandered, and he totaled his car en route to a gig at Orchestra Hall about four years ago. He no longer drives. He no longer travels out of town, with 2017 his last appearance in his beloved New Orleans, thanks to a friend who shepherded him around JazzFest.

"I couldn't remember people's names. It was terrible. I didn't like it. I still don't," Thompson said. "It could be worse. It's strange to have something that is making you not yourself."

But he still plays piano every day for two, three or four hours in his St. Paul home, though he has given up on the clarinet. He listens to records and "adores our two dogs, which makes a big difference," Niedenfuer said.

'Prairie Home' to Broadway

Growing up in Marine on St. Croix, Richard Thompson Jr. started piano lessons at age 6. There were two pivotal moments in his childhood: seeing a movie at village hall of a youngster, Sugar Chile Robinson, playing boogie-woogie with tiny hands, and, at his own junior high talent show in 1956, getting a rousing reaction to his boogie-woogie piano treatment of Bill Haley & the Comets' "Rock Around the Clock."

As a kid, Thompson became a serious record collector of jazz, which his father touted, as well as rock 'n' roll and R&B. His interest was further fueled by attending Minneapolis concerts by jazz star Louis Armstrong (Butch got his program autographed) and classical piano master Arthur Rubinstein.

At Stillwater High School, Thompson pursued the clarinet, which he'd started playing in sixth grade. With some classmates, he formed Shirt Thompson and His Sleeves to play at dances while also guesting with local amateur jazz ensembles.

In 1961, while attending the University of Minnesota, the clarinetist sat in with the Hall Brothers New Orleans Jazz Band of Minneapolis. A year later, he officially joined the group, playing seedy Hennepin Avenue bars even though he wasn't old enough to buy a drink. Then, two months after signing on, Thompson made his first trip to the Crescent City in Hall Brothers cornetist Charlie DeVore's 1957 Chevy.

"When I got to New Orleans, I was just sold on that music," he declared.

After a two-year stint in the Army, Thompson returned to the U, pursuing American studies and more music. Since the Hall Brothers gigs couldn't pay all the bills, he did a stint as newspaper reporter and then taught ragtime piano and jazz history at the West Bank School of Music.

In 1974, Thompson became house pianist — and eventually music director — on Garrison Keillor's new radio program, "A Prairie Home Companion," and stayed on for a dozen years.

The classical world also beckoned for a featured soloist at pops concerts, starting in 1987 with Thompson's performance of "Scott Joplin Suite for Piano and Orchestra." The pianist/clarinetist traveled the world, playing everywhere from Tokyo to Cairo.

He has released more than two dozen albums under his own name and appeared on numerous other records, including a 1996 Grammy-winning project by trumpeter Doc Cheatham.

A noted jazz historian, Thompson served as a consultant for the 1992 Broadway musical "Jelly's Last Jam," though he was not happy with how the musical director diluted the piano jazz of Jelly Roll Morton.

For 25 years, the collector and historian hosted "Jazz Originals" on KBEM-FM, educating jazz lovers about music and musicians, before signing off in late 2017.

Balluff was a devoted listener to Thompson's radio program.

"Here's a guy in the Twin Cities, so far away from the birth of this music in New Orleans, who is really an exemplary representation of the music," said Balluff. "And he became nationally known for it. That's a treasure for Minnesota."

'Moments of true beauty'

Niedenfuer isn't sure how Thompson feels about his performance on the new Southside Aces album, "How Long Blues," which was recorded live last fall at Crooners supper club in Fridley with longtime mentor DeVore sitting in on vocals.

"I think he has mixed feelings about it," she said. "He knows his playing isn't as good as it used to be. I don't know how discerning he is anymore. He likes Tony and the guys. He says he likes it. I think he's accepting it."

Said Thompson: "I'm happy that I can still play the music, and I remember pretty much how to do it."

Balluff is thrilled to play and record with Thompson, whom he's known for 22 years.

"It's amplified our normal focus as an ensemble," said the bandleader, who, along with his sidemen, are young enough to be Thompson's sons. "We're there to lift him up. Then he plays something, and you think, 'We get to be here because of him.' "

Balluff, who also has Vikings disease but hasn't yet required hand surgery, marvels at Thompson's fortitude and formidableness.

"I think about him not only adapting to his hands but adapting to his memory loss," Balluff said. "For me, I noticed that I didn't notice. It's produced moments of true beauty.

"When he was playing 'How Long Blues' during the [live] recording, I was listening to the miracle of the music finding its way to his hands and finding new routes to get there. He just presses on. His brain sends the music to his hands. It's amazing."

Twitter: @JonBream • 612-673-1719