The Ditty Bops are the Los Angeles duo of Amanda Barnett and Abby DeWald. They sing harmonies, accompanying themselves with mandolin, guitar, and dulcimer (and sometimes a slide whistle or what have you), and their music draws on folk, ragtime, psychedelic pop, early jazz, and Western swing. But the real fun begins with the theatrical and interactive side to their shows, with everything from puppets and skits to onstage drawings to an unending variety of costumes--gangster's moll, Lone Ranger, prom dress, superhero, or whatever catches their attention at the local costume shop. Their show is never the same twice! Or even from moment to moment, for these women do the quickest costume changes in the business. They have appeared twice on "A Prairie Home Companion" and been heard six times on the soundtrack to "Grey's Anatomy." The Ditty Bops' latest album, "Summer Rains," earned a Grammy nomination for Best Packaging.