Chicago is always changing. Out with the old: goodbye Marshall Field’s, Sears Tower and a competitive Bulls team. In with the new: hello Macy’s, Willis Tower and Fred Hoiberg.

A few good things don’t change, however. Terri Hemmert, the friendly midday voice on WXRT-FM, both DJ and station bedrock in a shifting city. Hemmert is heard daily from 10 a.m. to 1 p.m., as well as her “Breakfast with the Beatles” Sunday mornings. She has been spinning records — then CDs, then .wav files, which don’t actually spin — since I was in the 7th grade.

Hemmert turns 70 Saturday. I caught up with her a few hours before she flew to New Orleans for, she estimates, the 30th time, to revel in this weekend’s Jazz and Heritage Festival.

“I’ve been way too busy, overwhelmingly busy. I’m worn out,” she said, not sounding worn out at all. “Everybody keeps saying: you can relax when you get to New Orleans. And I tell them: ‘you’ve never been there, have you?'”

Here Hemmert laughed, something she does often and well.

Did she mind my spotlighting her turning 70?

“Oh no, that’s OK,” she said. “People know, if they do the math. I’m coming up on my 45th anniversary. It beats being dead. As [fellow ‘XRT DJ] Lin Brehmer says, ‘It’s great to be alive.’ I was so unhealthy as a child; I had rheumatic fever. They didn’t think I would make it to my 40s.”

Terri Hemmert as a child in Ohio

Terri Hemmert grew up loving music in Piqua, Ohio; her mother Betty was a music teacher and, in a very real sense, so is she. | F. Hemmert

Ever think about retiring?

“Why walk away as long as they want me here?” she asked. “I’m happy here. I have a million things to do that are still compelling to me, still fun. I still get to do something for someone, and if you’re not doing something for other people, you’re not living right. This gives me a lot of opportunities to do that. Teaching.”

She has taught college for more than 30 years.

“My students still like me,” says Hemmert. “I have a great class at Columbia College, “The History of Rock and Soul.” That’s why I’ve been so busy.” She has narrated five concerts over the past two weekends.

Hemmert listens as well as talks — not a universal among college instructors — and is encouraged by what she hears.

“I really like this millennial generation,” she said. “They’re not as hung up on really stupid stuff like racism and homophobia. They’re not ageist.”

As opposed to a certain self-regarding cohort that grew up in the 1960s.

“‘Never trust anyone over 30,'” Hemmert scoffed. “That’s so stupid. I can’t believe they said that.”

We talked about music, how beneficial it is for young people, particularly during our current political times.

“Music isn’t just something to dance to, to make out too,” she said. “It’s good to see musicians stepping up.”

Hemmert’s bringing something new to New Orleans this year — a cane, the result of several back surgeries.

“I’m always in pain,” she said, a rare cloud drifting across her general sunniness. Hemmert also battled cancer two years ago, and had to give up her beloved dog because she could not walk her. “I kinda slowed down. I love going to Metro, but the steps…”

The cloud passes quickly.

“I feel so fortunate,” she said. “I hear from people with stories that blow me away — I played a certain song, by luck, and the song they needed to hear was what I happened to play. Songs that give them the strength not to be broken, to see a little light.”

She mentions her mom, Betty, a music teacher.

“She taught me a lot about living,” Hemmert said. “What’s important. What’s not. Nobody wants to live with a jerk, so don’t be a jerk, because you have to live with yourself.”

“I’m not trying to be younger than I am,” she said. “Being older is not that bad. Sure, my body’s falling apart, but there are compensations. I’m finding wisdom and understanding and patience, less tolerance of BS. There’s a payoff, a balance, if you do it right. I’ve dodged a lot of bullets in my life. I’m happy to be here.”

Saturday, Terri Hemmert will be in the Big Easy, celebrating her birthday at her favorite restaurant, Elizabeth’s, with family and friends around her.

“I walk into my 70s unafraid,” she said.