Chris Ballew, lead singer for mid-'90s Seattle alt-rock outfit The Presidents of the United States of America, has a pair of Grammy nominations under his belt. His hit singles "Lump" and "Peaches" are fixtures on rock radio. So it's amusing that Ballew reentered the public consciousness, not as a middle-aged headbanger, but as children's music performer "Caspar Babypants." His eight albums for tots since 2009 have featured artists as diverse as Krist Novoselic and "Weird Al" Yankovic. Mr. Babypants is a hot commodity among hipper parents, with numerous shows in Portland and Seattle (and on KEXP) over the last two weeks alone.

His upcoming performance in Tumwater, however, will be something extraordinary. It's a benefit for Apple Tree Procuctions' Special Needs Acting Showcase, a drama camp for kids with developmental disabilities. Heidi Fredericks, founder of Apple Tree and drama teacher at Tumwater High School, met Ballew after a Babypants concert and struck up an email conversation. "My son (Oscar, 6 and half) just adores him," she says. "His music has changed our life. Oscar really only spoke in ABCs for a long time. ... One of our therapists recommended a Caspar Babypants CD. It just lit Oscar up! He would sing Caspar songs but also use them to answer us. (Caspar's) been a big influence to Oscar, and a wonderful man, very approachable, personable and kind. He's moved his schedule around quite a bit to make this concert happen for us. And parents love him, too. It's not obnoxious baby schlock, it's good music that just happens to have lyrics that are catchy to kids."

I ask Fredericks about her summer students. "The autism spectrum is gigantic," she replies. "Someone said to me, ‘Once you've met one kid with autism, you've met one kid with autism.' We work with all ages and ability levels. I think our youngest was three, and our oldest 22. We've had Down syndrome students as well; some kids that are verbal, some nonverbal; some that are really functional, and some like my son, who are working toward being more functional. We have the whole gamut."

I ask Fredericks if there's a way for folks to aid her worthy cause even if they can't catch the Babypants show April 11. "Oh, we would be so grateful," she says. "They can send me an email (at heidilf8@gmail.com), and I can give them more information." Both she and I have spent decades working on shows that "merely" entertain, a noble pursuit in its own right. But by working together, Apple Tree Productions and Caspar Babypants can achieve something quite a bit more impactful: it can help a unique kid near you find a voice.

CASPAR BABYPANTS, 2:30 p.m. Saturday, April 11, Tumwater High School, 700 Israel Road SW, Tumwater, $5 per family, 360.359.6685