"Baa, Baa, Black Sheep" is an English nursery rhyme, the earliest printed version of which dates from around 1744. The words have not changed very much in two and a half centuries. It is sung to a variant of the 18th-century French melody Ah! vous dirai-je, maman. Modern versions tend to take the following form: Baa, baa, black sheep, Have you any wool? Yes, sir, yes, sir, Three bags full.

Source: Wikipedia