Yigdal Elohim H̱Ai (Glorify and Praise the Living God)
In this Piyut the author, R. Daniel ben Yehudah, the Judge of Rome, who lived in the 13th century, lists the thirteen Principles of Faith as phrased by Maimonides in his commentary to the Mishnah. The Piyut gained great popularity, was adapted to many different tunes, and incorporated into most traditions. It is genreally sung at the end of the prayer service. Many authors tried to imitate the Piyut and some even wrote parodies. Interestingly enough, R. Yitzchak Luria Askenazi opposed this Piyut, mainly because he disagreed with defining and declaring principles of faith. As a result, those who follow his rulings do not include ‘Yigdal’ in their prayer books.