Sing a song of sixpence
From Longman Dictionary of Contemporary EnglishSing a song of sixpenceˌSing a ˌsong of ˈsixpence a nursery rhyme (=an old song or poem for young children) which starts: Sing a song of sixpence, /A pocket full of rye;/Four-and-twenty blackbirds/Baked in a pie./When the pie was opened, /The birds began to sing, /Wasn't that a dainty dish/To set before the King?