The Bat Jamboree was held early this year, at the old drive-in movie not too far from here. It was standing room only as the houselights went down. The spotlight came up -- there wasn't a sound Then: 1 bat sang.2 bats flapped. 3 bats cha-cha-ed4 bats tapped.Every year a troupe of 55 buoyant bats comes up with 10 fabulous acts to entertain and instruct an enthusiatic audience. And every year the bats top themselves when they perform the grandest finale of all . . . With its exuberant text and enchanting illustrations, Bat Jamboree is both a counting book and a thrilling theatrical event.