Janis Joplin’s pals say she would have dug it. The Haight-Ashbury hipsters around the corner couldn’t care less.

And most important, 20 homeless drug-addicted mothers and their babies will get a new lease on life because of it.

The happening?

Thirty-one years after she dropped her last hit of acid there, rock legend “Pearl” Joplin’s funky old house in San Francisco is being turned into a drug rehabilitation center.

If the four-story Victorian at the corner of Lyon and Oak streets could talk, it would tell wild tales of the hippie days in 1967 and 1968 when Joplin played and laughed beneath its peaked roof on her way to stardom. Country Joe McDonald, Jefferson Airplane and the other rock icons who hung in the Haight back then remember the stories — but to look at the place today, you would never know what went on there.

After a yearlong $350,000 renovation, the building’s nine rooms are painted muted yellow and shiny white, and new cribs and beds dot the whistle-clean bedrooms. Tidy offices for Golden Gate Community Inc., the nonprofit that will run the rehab center, cover the top floor, and the edgiest thing on any bookshelf is the Sesame Street adventures of Oscar the Grouch.

There aren’t even any stereos anywhere — music is too distracting to people trying to live together and shake drugs, said Golden Gate Executive Director Randy Newcomb.

It is a far cry from the days when the living room was painted black, booze bottles abounded, live “Piece of My Heart” renditions jangled the air and a whole wall was plastered with posters of a bare-breasted Joplin herself. But then, the change is totally appropriate, said McDonald, who once lived there as Joplin’s boyfriend.

Considering that the Haight was once the world’s epicenter of sex, drugs and rock ‘n’ roll, what could be a better use for one of its historical shrines than a quiet, healing refuge for addicted mothers?

“I think Janis would be really pleased and happy to have this happen,” said McDonald, who became enamored of Joplin while tripping on acid at a mutual gig of both their bands in Berkeley. “Really, she was just a regular person who had simple pleasures and liked family life.

“She’d like to know something good was being done with that house.”

Newcomb said the rehab center, known as Oak Street House, will open June 19 to house 20 mothers and their babies. The women will be able to stay two years if they participate in a host of outside and in- house programs giving counseling on addiction, parenting, and employment.

Golden Gate has owned the 103- year-old house since 1981 and used it for everything from a crisis center to a homeless shelter. The idea of converting it to its new purpose came in 1995, when directors of the nonprofit and the city’s homeless- aid department brainstormed on how to address the increasingly severe shortage of beds for homeless

families. They wound up getting $800,000 in startup grants.

“If you track homeless families, you find the best opportunity to get clean is when a woman is pregnant or has an infant,” said Newcomb. “We will give them that opportunity.”

Joplin moved into the house in 1967 after getting tired of commune life in Marin County with her band, Big Brother and the Holding Company, at a time when she was merely part of a hot local act with no radio hits.

While there, she perfected her stutter-talk style of blues singing and exploded into prominence with her now-legendary performance at the 1967 Monterey International Pop Festival, recalled McDonald, who was a hit himself in Monterey.

“It was a big deal for her to get her own place,” McDonald recalled. “I was in Berkeley with my band at the time, didn’t have a car and had to hitchhike to San Francisco, so she let me live there about three months.”

There’s not a trace of anything Joplin-ish in the house today, and there are no plans to install any tributes, said Golden Gate directors. The only thing that will look the same will be the outside–which has the same wide Victorian windows, curlicue frescoes and beige color scheme it had in 1968, although there is now a splash of purple thrown in.

McDonald, who today is a clean- living peace activist in Berkeley, still doing music, said while they were in the house, the ever-volatile Joplin asked him to “write me a song before we get too far apart,” so he obliged. The result was “Janis,” in which he sings, “Into my life on waves of electrical sound and flashing light she came,” which pretty much sums up a lot of the feeling of the day.

The two broke up, and then in 1968 Joplin was evicted over a dispute about her dog. She charted a string of hits with her trademark blues-screech style, became the generation’s leading symbol of drug-and-booze-addled rock stardom, and died Oct. 4, 1970, of a heroin overdose in a Hollywood motel. She was 27.

After she left the house, it became headquarters of an LSD-loving religious cult. Then Golden Gate bought it.

News of the Joplin house’s new incarnation fetched little more than a yawn yesterday in the hip heart of the Haight, where as with many things ’60s, Joplin is mostly a faded memory good for selling memorabilia and old recordings. Bus tour guides point out at least three different houses on Lyon Street as being Joplin’s, including the one that truly is, but the locals rarely bring her up.

“Heck, Jimi Hendrix used to live in this very building, but really, who cares that much?” said Brian Friedman, the thirtysomething owner of the Anubis Warpus store of rebel- cool knickknacks on Haight. “In their day, that was their scene, but it’s old and worn out.

“Janis just isn’t that modern any more,” he said with a smile.