Mark Cohen has a great new book out on Allan Sherman. I'll be posting a long rave here shortly but if you don't want to wait for that, you can order it here. And Marc has also been posting some Allan Sherman rarities online. This is not one of Mr. Sherman's better efforts — an early Porgy & Bess parody from back when he thought his audience was exclusively Jewish and would laugh at anything that mentioned The Catskills, shmaltz herring or the garment district. But it's an interesting curio of Sherman's development and it's short…