What an event! What a show! It's catchy and quirky. Tuneful and toe-tapping. Exuberant, unexpected, and utterly endearing. It's what happens when you take America's beloved illustrator and children's author and combine her buoyant genius with some of the most talented people on the stage&mdash;presenting <i>Philadelphia Chickens</i>!<P> Created by Sandra Boynton, <i>Philadelphia Chickens</i> is a family musical in a book, bringing together a full-color songbook of 17 1/2 illustrated story-poems with a full-length, fully orchestrated CD of original songs performed by the likes of Patti LuPone, Kevin Kline, Meryl Streep, The Bacon Brothers, and Laura Linney, who pleads "Please, Can I Keep It?"&mdash;it followed me home. / What exactly it is/ I don't know. Also joining in are Eric Stoltz, Natasha Richardson, Scott Bakula, and two Boyntons, including daughter Caitlin McEwan, who performs a piece that every little listener will relate to&mdash;a love song to the chocolate chip cookies that are just out of reach. With the collaboration of composer Michael Ford (known to Boynton fans from <i>Rhinoceros Tap</i>), <i>Philadelphia Chickens</i> is that rarest of kids' musical discs&mdash;one whose inimitable lyrics and music make it as sing-along, dance-along, cluck-along for parents as it is for their children.