That curious Boynton pizzazz takes to the stage in Philadelphia Chickens, a zippy musical production for kids and way beyond. And just wait till you hear who's in the cast...The Seldom Herd sings "Cows"Meryl Streep sings "Nobody Understands Me"The Bacon Brothers sing "Philadelphia Chickens"Keith Boynton sings "Be Like a Duck"Laura Linney sings "Please, Can I Keep It?"Eric Stoltz sings "Snuggle Puppy"Patti LuPone sings "I Like to Fuss"The Bacon Brothers sing "Snoozers"Caitlin McEwan sings "Faraway Cookies"John Stey sings "Fifteen Animals"The Heath Sisters sing "Belly Button" (round)Kevin Kline sings "Busybusybusy"Michael Ford sings "Those Dinosaur Bones"Darcy Boynton chants "Dinosaur, Dinosaur"Beth Andrien sings "Jump Rope Jive"Scott Bakula sings "Pig Island"Adam Bryant sings "Pajama Time"Natasha Richardson sings "Silly Lullaby"Aaaardvarks (Mark Linn-Baker, Joe Grifasi, Michael Gross & Devin McEwan) sing "The Intermission Song" With these performers, words and pictures by Sandra Boynton, and music by the incomparable Rhinoceros Tap team of Boynton & Ford, you have to hear it to believe it. And even then, it may take a while.