Every musician wants to make an album that has an indelible impact on his or her generation. In 1993, Liz Phair did that with her debut, Exile in Guyville, a stinging examination of sex, self-worth and ego in the alt-rock subculture.

But there's another side to making an iconic album. Where do you go from there?

To most of her fans, Phair was supposed to stay the same confused 26-year-old, making the same left-of-center music forever.

So when the singer released her self-titled, fourth album in June, her die-hard fans were amazed at what they heard: a slickly produced record that bore the hallmark of hitmakers such as the Matrix, who helped propel Avril Lavigne to stardom.

The reaction was swift and harsh.

But Phair, who plays Sunday at Bowery Ballroom and then hits the far-bigger Roseland Ballroom for a second show on Wednesday, says she's happy with her music and will weather the storm.

"I don't think too much about it, because I'm kind of busy touring," she says. "I've gone back and listened to the record myself, and I really like it.

"So I kind of just have to suffer their ire and move on."

The mother of a 6-year-old, Phair had decided that she wanted to make a pop album that had a shot of hitting the charts, rather than the midmarket alt-rock she had been making.

"I'm a mom and I'm 36 and that's my M.O.," she says. "This is not my life - this is my work."

But while older fans may be surprised by Phair's newfound love of soaring harmonies, beneath the veneer there's still a good amount of her ribald sensibility. She sings about dating younger guys for their stamina and disposability, and celebrates raw sexuality with a frankness that is rare in pop.

The gamble may have paid off, as a younger generation of fans is finally discovering the singer. It's good for Phair, but has so far resulted in some odd crowds, where aging hipsters mingle with fresh-scrubbed teenagers trying to look worldly.

"I feel like we should set up a groom's side and a bride's side," Phair says of her concert demographics.

"The old ones would be cheering against the new fans -- who are young girls -- and the girls could cheer against them."