Rock-a-bye, baby—with an emphasis on rock—is the accent of this collection of tunes by pop idols aimed at the Sesame Street set. There are no suggestive lyrics, and when Ernie and the Cookie Monster sing a ditty titled Share it’s not about Sonny’s ex; it’s about the virtues of generosity. The Doobie Brothers contribute a rousing rendition of Wynken, Blynken and Nod, Linda Ronstadt teams up with Wendy Waldman on a delightful original called/Want a Horse, and a similarly fresh Blueberry Pie is handled sweetly by Bette Midler. Other highlights are Dr. Spock rockers by Al Jarreau, George Benson and Dr. John, who sings a duet with Libby Titus called The Sailor and the Mermaid. But the heroes of the project are the musical Taylor-Simon clan: Lucy Simon produces, and her sister Carly and in-laws James, Livingston and Kate Taylor all contribute material. The overall result is a record that is as much grownup fun for kids as a Maurice Sendak book and the most impressive massing of rock talent since the No Nukes affair.