When Karen O was trying to compose music for the rumpus scene in the feature film adaptation of the beloved children's book "Where the Wild Things Are," she would think about writing for kids -- and run into a wall. "The first few versions kept falling prey to being upbeat and happy," said O, the lead singer for the rock band Yeah Yeah Yeahs. "As soon as we'd start doing that, I felt specious, like I was writing for a Muppets movie."

So the 30-year-old songwriter, who is not a parent and had never written anything specifically aimed at children before, stopped thinking about the audience. Instead, she focused on what she and the team of A-list indie-rock musicians she assembled did best. The approach worked. Singing in her reverb-free tomboy yelp, Karen O and the Kids' playful songs provide the expressive heart of director Spike Jonze's emotional movie.

In the same way as Jonze's movie and Maurice Sendak's original book do, O's soundtrack stretches our idea of what children's media can be. "Kids respond to music that's pure of heart," O said. "They're emotionally complex little human beings."

Like O, a slew of musicians from the worlds of rock, folk, alternative, reggae, country and hip-hop are expanding the edges of what family music can and should sound like. Dan Zanes, Ziggy Marley, Laurie Berkner, Ralph's World, the Sippy Cups, Justin Roberts, Elizabeth Mitchell and many more are creating for the under-10 set -- and their parents -- the sort of listening alternatives that grown-ups have enjoyed for years. As Dan Perloff, founder of the new Venice-based label Minivan, said: "There's a lot out there that's not Disney."

Kids stages have sprung up at major festivals such as Stagecoach and Lollapalooza. Moodsters the Shins and hip-hop band the Roots have contributed songs to the new album "Yo Gabba Gabba! Music Is Awesome!," based on the popular Nick Jr. TV show. Ozomatli, Los Lobos and the Decemberists are all putting on family shows. There's even a groaner name for some of this music: kindie rock.

Kindie rock is subject to many of the same charges of eliteness and boutique trendiness as its "parent" genre, indie rock. But at their best, the new makers of music for kids offer live and recorded cultural experiences that parents can share with their offspring without suffering the aural equivalent of having pigged out on cotton candy. They also provide kids a way to understand music that's not as distancing as taking in a big show.