"So, how is everybody doing tonight?" Mary Tjosvold asks the full house in the Dunsmore Room at Crooners Lounge and Supper Club in Fridley. There is a smattering of applause.

"Oh, you have to be doing better than that 'cause Robert Robinson is here," she continues. The applause increases manifold.

"Remember, this is the Dunsmore Room. Oh, by the way, I'm Mary T, the proud owner. It's all about Robert Robinson and his band tonight. Put the world aside. Put your phones away."

Tjosvold means business. Before gospel star Robinson is finished with his performance, she's even sssshing a couple to let them know they can't dance in the Dunsmore even though the singer is interpreting, ironically, LeeAnn Womack's country/pop classic "I Hope You Dance."

At Crooners, Tjosvold is part cheerleader (she actually played basketball in high school) and part scold (she was an inner-city math and science teacher at one point). She's new to this night job.

As a businesswoman in health care for 40-some years, a part-time activist and a full-time humanitarian, she jumped into the restaurant/music room business nearly four years ago.

At age 75, she's got more energy than a case of 5-Hour Energy, more heart than a shelf full of Valentine cards and more save-the-world ideas than Oprah Winfrey.

"I want to make a difference. I've always had that phrase in my head," Tjosvold explained recently. Even if it's one person at a time.

Twin Cities vocalist Patty Peterson understands Tjosvold's impact.

"Mary T had a vision and she was going to make sure it would happen," said Peterson, who performs regularly at the Fridley establishment. "She doesn't have to talk about it. She just does it. It's her mission to give back. That's who she is. And it's very powerful."

The other afternoon, before any musicians showed up for sound check, Tjosvold sat in the acoustically superb Dunsmore Room overlooking sun-splashed Moore Lake. She talked about her approach and philosophies in her various endeavors.

"For me, it's about responding to what people are saying," she said. "We listen to people. Just like in our health care [businesses], you always have to listen."

And she listens to people who know the ropes. Like restaurant consultants. Like Crooners music director Andrew Walesch. And her globe-trotting, piano-playing husband, Larry Dunsmore, who died a year after Crooners opened in late December 2015.

Crooners' 90-seat listening room with its grand piano is named for him. It's one of two music rooms in a space formerly occupied by the Shorewood supper club. After having the large Shorewood bar removed from the middle of the room this spring, Crooners lounge now seats 225 with good sightlines.

Even though neophytes might be intimidated by the Fridley location (a mere 15 minutes north of downtown Minneapolis), Crooners seems to have hit its stride. Shows sell out in the Dunsmore for the likes of jazz stars Bobby Lyle and Sheila Jordan. Local favorites such as Davina & the Vagabonds and Wee Willie Walker draw crowds to Crooners lounge.

"We're not profitable yet, but we will be," Tjosvold said. "They say it takes about five years for restaurants to be profitable."

She knows numbers. She employs 75 at Crooners (her night job) and 1,200 at her health care businesses (her day job) in Minnesota, Maryland, Wisconsin and Arizona — senior residences, assisted living, rental housing, hospice, housing for people with brain injuries and in-home care.

"I realize you can make a difference in your employees' lives. And you can use the money from your business to make a difference in people's lives," Tjosvold said. "In the Dunsmore, we're giving people a gift of two hours when you don't have to think about family issues or money or what's happening in the world."

Activism in her DNA

Whether starting a nursery and grade school in Cameroon, serving 12 years on the board of the American Refugee Committee (including four as chairwoman) or presenting top-shelf music, Tjosvold wants to affect people's lives.

It's in her DNA.

Her grandparents used to feed the homeless in a park by Minnehaha Falls. Her grandfather helped found the DFL Party. Living in Austria as an AFS student from Minneapolis Roosevelt High School opened Mary's eyes to the world — and travel.

In her 20s, Tjosvold developed endometriosis, which caused her to rethink her life.

"I realized that the way you survive is one day at a time," she reflected. "That had a huge, really positive impact on my life. Today is the day you live for."

She wanted to become a community organizer with her hero Saul Alinsky in Chicago. But her college professors discouraged her as she earned a Ph.D. in education administration from the University of Minnesota because she was "too outspoken."

So Tjosvold figured she needed to go into business for herself. When grandma willed some farmland in Coon Rapids, Tjosvold and her mother, Margaret, decided to continue grandma's work as a nurse by building a home for seniors there in 1971.

"My grandmother grew up with five brothers on an Iowa farm, and she just believed she could do anything her brothers could do," Tjosvold said. "My mom said I inherited her [grandma's] positiveness — everything was possible."

In the 1980s, when she was working with women named Mary Ann, Mary Ellen and Mary, the staff decided to dub her "Mary T," and it stuck. In fact, her businesses are under the umbrella Mary T Inc.

The "T" could just as easily stand for "travel" because Tjosvold's passport includes a recent trip to Thailand to fight sex trafficking and one to Uganda to help outfit people with eyeglasses as well as previous missions to such war-torn nations as Rwanda, Gaza and Bosnia.

Around-the-world romance

Tjosvold played bass drum in her marching band in junior high school and took saxophone and organ lessons. As a music fan, she was drawn to Glenn Yarbrough and Joan Baez, folk singers with a message.

But something turned her head around musically — and otherwise — in 2009. The staff from her Arizona business invited Tjosvold and her mom (who turns 100 in October) to go on a cruise to the Panama Canal area.

Although that kind of trip is not Tjosvold's cup of tea, she decided to go — and committed to trying everything. So she went to watch the cruise ship's comedian, and the hypnotist and the lounge crooner, who invited her to jump atop his piano à la Michelle Pfeiffer in "The Fabulous Baker Boys" movie. And, to the surprise of her traveling party, she not only did it but lifted her leg to show off her red shoes, which, unbeknownst to everybody in the audience, is what the hypnotist had programmed her to do.

The well-traveled piano player asked Tjosvold to tea. And then the charming Brit — who had played with Ella Fitzgerald and Barry Manilow and performed at the 1981 engagement party for Prince Charles and Lady Diana — romanced Tjosvold around the world. In 2013, she married for the first time, and the couple settled into the family property in Coon Rapids.

One day the following year, Tjosvold and Dunsmore were driving on Hwy. 65 in Fridley and saw a single car in the parking lot of the Shorewood supper club, stopped and learned that the shuttered building was about to go on the market.

Tjosvold bought it, spent hundreds of thousands rehabbing it and opened Crooners in the fall of 2014.

"I don't do strategic planning; I'm much more intuitive," said the entrepreneur.

She's had lots of successes and some failures, including buying an art deco movie theater in Red Wing and a psychiatric hospital in Prescott, Wis.

A year after Crooners opened, Dunsmore died of cancer.

"We had separate lives. Some couples are more attached at the hip. I don't know how they survive when one of them dies," said Tjosvold, who'd never had a close family member die except her 96-year-old remarried father. "For me, it was getting up every day and coming here [Crooners] and making part of the dream come true and the legacy to [Dunsmore] come true."

Tjosvold has incorporated many of Dunsmore's ideas into what she calls Crooners protocol — always introduce the acts; no dancing in front of the stage; serve food and drinks only between songs; no ice cubes in the water pitchers (they make noise when you pour); bartenders don't use blenders; and don't present bills to customers until after the music is done (unless they request).

Unlike at most bars with music, alcohol sales are not a top priority for Tjosvold.

"That's not who we are," she said. "An intimate listening room is what the Dunsmore is."

Even though she enforces rules to respect the listening-room atmosphere, Tjosvold is sensitive to her Crooners customers. She reads every e-mail. Like the man who complained that singer Robert Robinson mentioned Jesus when he offered the hymn "The Old Rugged Cross." The e-mailer said he'd experienced Robinson in concert before.

So Tjosvold discussed the situation with Walesch, her music director.

"Since he'd seen Robert before, I told the man that he must have known Robert Robinson was a gospel singer," Tjosvold told Walesch. "What did he expect?"

Said Walesch: "You did the right thing."

Twitter: @JonBream • 612-673-1719