Piyyut is Jewish liturgical poetry, in Hebrew or occasionally Aramaic. Since the fifth century CE, piyyutim (the plural of "piyyut") have been written in many different genres and subgenres. Most of these are defined by the function that the given poem fulfills in the context of Jewish prayer service; but a few are defined by other criteria, such as content. —a series of piyyutim, which adorn the blessings of the ‘Amida. There are a few types of these: Some Shiv‘atot, almost exclusively for great festivals, have expansions: Azharot ElohekhemMagen Avot piyyutimZemer (usually for the Sabbath).