Mille Cronin loved musicals. So when her son Kevin Cronin’s power ballads were featured in Broadway’s “Rock of Ages,” of course, she went to New York City to see the show.

“It was always Mom’s dream to sing in a Broadway show,” said her son, the frontman for the band REO Speedwagon. After taking them backstage to meet the actors, “The house was empty. So my mom and dad walked out on the stage and sang a song together.”

It was the same number they sang when they came to the front window to say goodbye to their kids or serenade people leaving a party. It went:

“We wish to say goodbye to you

Farewell and adios and adieu

We really hate to go

Because we love you so

It’s time to say farewell to you.”

After they finished, “She could say she sang on Broadway,” Kevin Cronin said.

Mrs. Cronin died Friday at home in Oak Lawn of complications from Lewy body dementia. She was 93.

Charismatic and always ready to break into song, “She brought a party wherever she was,” said her daughter Maura.

Mrs. Cronin and her husband Ted helped raise money to expand St. Linus School, which in the 1960s was full to bursting with students born during the baby boom, according to Margaret Hayes, a former student who’s now the Oak Lawn school’s principal.

Mrs. Cronin was part of a group that brought in more than $1 million for an addition by mounting “Way Off Broadway,” a musical fundraiser Hayes said began around 1971 and continued almost every year until 2005.

The main musical, in the gym, was called “Palace Revue.” Four smaller shows took place simultaneously elsewhere in the school.

“There were 2,500 people in the building at night, and they would go from show to show to show and then the Palace Revue,” the daughter said.

To create “Way Off Broadway,” Mrs. Cronin condensed Broadway musicals, directed, did choreography, organized crews and rehearsed the parent performers.

Mrs. Cronin’s rendition of “Ring Them Bells” was always a highlight.

Ticket sales “raised more than $1 million,” according to Hayes, allowing St. Linus to build an addition, expanding from about 12 classrooms to 30, plus a gym.

“The Cronins were in it or involved almost the whole time,” Hayes said. “There were little subdivisions in Oak Lawn, and many of the people didn’t know each other. After ‘Way Off Broadway,’ that all went away. Everybody knew everybody.”

After Hayes’ mother Marie appeared in the show, she wrote to Mrs. Cronin: “You completely changed my life.”

“My mother said in this letter she used to just go to church and go home,” Hayes said. “Once she joined ‘Way Off Broadway,’ the whole world opened up to her. All of a sudden, priests were saying, ‘Hello, Marie,’ and people in the back of church were saying hello.”

Born Mildred Stanek, Mrs. Cronin grew up on the South Side. Her father “would pick up any instrument and could just play music on it,” her son said.

But he was an alcoholic, and, when Mille was 18, his wife left a note to say she was leaving, Maura Cronin said. “She overcame a lot,” she said of her mother.

Young Mille met Ted at a soda shop near Mundelein College, where she majored in sociology and minored in theater. She went on to work as a social worker for Catholic Charities. After Kevin was born, the Cronins adopted three children through the social services agency.

“She was always playing records in the house, the famous Rodgers & Hammerstein shows, and it kind of rubbed off on me,” Kevin Cronin said.

Years later, when her granddaughter was trying out for a high school musical, Kevin Cronin said, “She coached my daughter Holly on how to audition. And, as a freshman, based on that audition, she got the lead in ‘Oklahoma!’ ’’

The Cronins raised their four kids on 53rd Avenue in Oak Lawn, later named Honorary Ted and Mille Cronin Way.

When she was diagnosed with Lewy body dementia, he told her: “We’ve had 60 great years together. So now we’ve got a few tough ones.”

Because of her dementia, she didn’t know her husband died in January, nor that their son Sean, who had diabetes, died hours before his father’s funeral.

“She never experienced the loss of my father, and he never experienced my mother’s death,” Kevin Cronin said.

In addition to her children Kevin, Maura and Lisa, Mrs. Cronin is survived by 11 grandchildren and two great-grandchildren. Visitation is planned from 10 a.m to noon Saturday at St. Linus Church in Oak Lawn, with a funeral mass at noon.

She loved jackets from Chico’s. So her family plans to bury her in one, along with the sequined bell applique she wore when she’d sing “Ring Them Bells.”