reference to a children's nursery rhyme: / "Sing a song of sixpence, / Pocket full of rye, / Four and twenty blackbirds, / Baked in a pie; / When the pie was opened, / The birds began to sing, / Was not that a dainty dish, / T o set before a king?" / From the occasional sixteenth century practice on festive occasions of imprisoning live birds in a pie so that they could fly forth and add to the excitement when the pie was cut. —SHSBC Binder 31 Approved Glossary