MOTHER LOVE: What started as a novelty act has become a real rock band.

In suburban garages across America, cars leak oil, rags sit too close to gasoline cans, suicidal sorts feed tailpipes into windows — and bands bang out raw renditions of “Louie Louie.” But in Sharon, there’s one garage that’s been a breeding ground for a very different kind of band. Because it’s not the kids who are making the musical racket in this garage, it’s their moms. And not just any moms: Lisa Yves (keyboards; 42), Marlane Pinkowitz (guitar; 43), Tammy Robbins (drums; 40), Emily Grogan (guitar; 38), and Marian (bass; 46 and, like Madonna, on a first-name-only basis with her fans) are HRT — Hormone Replacement Therapy. Although they’ve yet to release a debut CD, they’ve already been featured on The Today Show, The Fox25 Morning Show, and WCVB’s Chronicle. And last year, the Canadian cable channel Slice carried a reality show based on their lives. Negotiations are under way to bring a version of the same program — Rocker Moms — to a US outlet.

Despite the obvious novelty value of a group of rocker moms, HRT are more than just an A&R scout’s publicity stunt — they’re serious about the band, and they have two members who are seasoned vets. HRT co-founder and de facto leader Lisa is a Yeshiva-schooled NYC native who made a living playing piano in Greenwich Village before moving here to raise a family. (She also had a stint performing with Harry Connick Jr., but we won’t dwell on that.) And as a solo singer-songwriter, Emily Grogan has two albums to her credit: 2005’s iO and the new At Sea (One Way Productions). She’s also part of Angeline, a folk-rock project she formed earlier this year with fellow singer-songwriter Linda Viens.

Settled into the comfy-chair section of a Starbucks in Chestnut Hill, the members of HRT (who perform this Friday at Church) describe themselves only half-jokingly as MYLRs — Mothers You’d Like To Rock. There may not be anything particularly new about women in rock, but four decades after Janis, three after Patti Smith, and just one since the riot grrrl upsurge, HRT are emblematic of a grassroots shift. The spotlight has moved past mothers playing rock and roll to motherhood itself. Last December, HRT competed with other rocker moms at a Momapalooza festival in New York. And the MILF allusion is more than a joke: HRT are about rock and roll in the classic sense, with all the celebration of sexuality that goes with it. There was a genuine sense of liberation in the air when they played T.T. the Bear’s Place last spring. HRT offer the opportunity, as one mom in the audience put it, to “live vicariously through them.”

There are, of course, complications that come with rocking and raising a family. Not only a mother but recently divorced, Emily Grogan juggles work and her children’s welfare with her musical career. Two HRT songs, “Motionless” and “Full Circle,” deal with these issues in a musical-therapy sense. “Tequila” reveals a more hedonistic side of the band — the kind of release not usually found in the suburbs of Desperate Housewives.

And if some shtick creeps into the HRT songbook, that’s just the band finding their way. “In the beginning, our songs were very joky,” says Lisa. “But we’ve begun to get away from that. I think maybe we were a little defensive about what we were doing and felt that we had to excuse — or maybe defuse — it through humor. Now we’re more confident and we want to take our music seriously.”

“It’s definitely about the music,” says Emily, comparing HRT with the bands they faced off against at Momapalooza. “They were more concept bands, joke bands. Maybe they’ll change. We have.”

In part that change is a natural one, as HRT move up and out of the garage and hone their Heart-meets-Melissa-Etheridge brand of rock. (You can get a taste of “Tequila” and more HRT at www.myspace.com/HRTrocks.) It’s also a reflection of their transition from a fun DIY project to something a bit more serious. Not that HRT are making plans yet to take their kids on the road with them, but they are looking to the future.

“We’ll still be HRT,” says Marlane. “But by then it will stand for Hip Replacement Therapy.”

As laughter breaks out, two mothers with baby carriages glance over and smile. Yes, they look amused. But they also look complicit.

HRT | Church, 69 Kilmarnock St, Boston | October 12 | 617.236.7600