When my oldest child began the birthday party circuit for 2-year-olds, the swankiest Upper East Side fêtes featured a pixie-blond, guitar-toting rocker who memorized the names of every toddler in attendance. These were not your average shindigs for 2-year-olds. At chic clubs and restaurants that I hadn’t been to since my sweet-16 days, 30 or 40 preschoolers were mesmerized by the music — and memory — of Laurie Berkner.

Seven years later, no club can compete with the location of Ms. Berkner’s latest gig: Carnegie Hall. This Sunday at 1 and 4:30 p.m., the Laurie Berkner Band will perform at the Isaac Stern Auditorium.

“The first show sold out in an hour,” Ms. Berkner told me on Friday, “so we decided to go ahead and have a second show.” According to my latest search on eBay, it doesn’t seem as if adding the second performance has made tickets any easier to procure. Four tickets for the 4:30 p.m. performance were being offered for $200 — double their face value.

Ms. Berkner, the 38-year-old star of “Jack’s Big Music Show,” on Nickelodeon’s commercial-free preschool station, Noggin, said that her success doesn’t feel sudden. “It’s been a long road,” Ms. Berkner said. “Sometimes I do think to myself that a few years ago, things were really different. But there have been lots of little steps and lots of hard decisions along the way. Sometimes I can’t believe I’ve been doing this as long as I have,” she said.

Before becoming one of the most popular children’s recording artists in America, Ms. Berkner taught music classes to preschoolers. She also performed in her own all-female rock band. Writing original music for the adult bands was a struggle — but writing tunes for children turned out to be a snap.

“One of the things I love about writing kids’ music is its simplicity,” Ms. Berkner said. “You can have one simple, moving line that’s repetitive, and then make a little change, like add a chord or change a key and — oh my God, the sun has come out. It’s so exciting for children.”

Songs such as “I’m Not Perfect” and “The Story of My Feelings” reflect a running theme throughout many of Ms. Berkner’s songs. “I guess if I have any agenda, it’s that it’s important to like yourself,” she said. “That’s what I work on in my own life. And also, that it’s important to be comfortable with your feelings.” An illustrated children’s book called “The Story of My Feelings” (Orchard Books/ Scholastic), based on Ms. Berkner’s song, was released last month.

But Ms. Berkner is quick to note out that not all of her songs have a pointed theme. “I don’t sit down and think I want to write a song with a message,” she said. “Sometimes I write a song that’s about having fun, or is funny to say, or is about an image that I would have found funny when I was a kid.”

When Ms. Berkner’s daughter, Lucy, was born three years ago, she found a new source of inspiration. “Now that Lucy’s talking, she spurs things that I remember from my own childhood,” Ms. Berkner said. “We’ll have a funny interaction and I’ll think to myself, that’s something I want to write about.”

Ms. Berkner certainly knows how to appeal to the preschool set — more than 400,000 copies of her 2006 combination CD and DVD, “We Are … The Laurie Berkner Band,” have been sold in the last year.

When I told Ms. Berkner that her music reminds me of the 1972 album I listened to when I was a child, “Free To Be … You and Me,” she said that she, too, listened to Marlo Thomas’s star-studded hit that focused on individuality, tolerance, and happiness with one’s identity. “I loved that album,” Ms. Berkner said. “I also loved Peter, Paul & Mary’s album for children and the music of Hap Palmer. For years I listened to Palmer’s song ‘Sammy.’

“‘This is a song about Sammy,'” she began singing. “Sometimes I think to myself, that’s the kind of song I’m writing now.”

When I looked on eBay, I noticed that seats to Ms. Berkner’s concert at Atlanta’s Symphony Hall were also selling for multiples of their face value. I told Ms. Berkner that I felt like one of the city’s best-kept secrets had been discovered.

“I couldn’t have done this without New York City,” Ms. Berkner said quickly. “So many things kept coming together because of New York and the people I met here. Maybe I would have met supportive people anywhere, but there are so many people here, and many of them were personally supportive of me. They helped me sell my first cassettes, some even loaned me money, and some connected me to the producers of the “Today” show. Yeah, I don’t think this would have happened without New York.”

sarasberman@aol.com