Many "piyyutim" are familiar to regular attendees of synagogue services. For example, the best-known "piyyut" may be "Adon Olam" ("Master of the World"). Its poetic form consists of a repeated rhythmic pattern of short-long-long-long (the so-called hazaj meter), and it is so beloved that it is often sung at the conclusion of many synagogue services, after the ritual nightly recitation of the Shema, and during the morning ritual of putting on tefillin phylacteries. Another beloved "piyyut" is "Yigdal" ("May God be Hallowed"), which is based upon the Thirteen Principles of Faith set forth by Maimonides.