Every Friday afternoon, Terry McGill’s third-grade class clamors for their sing-along. McGill, whose night job is banjo player in the band Straight Drive, strums bluegrass standards for his New Jersey 8-year-olds. The laid-back elementary-school teacher says there’s no need for dumbing down his lyrics. “We’re not a specialty kids’ act,” says McGill. “But once they hear bluegrass, they get into it.” They’ll have the chance to listen to all sorts of twangy talent—including Straight Drive—at Carnegie Hall’s Bluegrass Celebration!, the Family Concert series finale on Saturday. McGill says the most he’ll do to make the concert more kid-friendly is avoid my-woman-done-left-me ballads in favor of life-in-America narratives. (“Orange Blossom Special” and “Rock Island Line,” both about railroads, are among his students’ faves.) On the double bill with Straight Drive is Ebony Hillbillies, which similarly has no children’s repertoire. (“We get them with the dance beat,” says Rique Prince, the band’s fiddler.) To further entice the young’uns, Carnegie has called on a pair of 14-year-old hosts, Ryan Holladay and Sierra Hull, both musicians from Tennessee, who’ll offer a brief history of bluegrass. With joints like Cowgirl becoming popular bat mitzvah destinations, it may be just a matter of time until the Apple goes as peachy as Atlanta.