As the second period of the school day begins at 9:00 am one Tuesday morning, students in the middle school of the Perelman Jewish Day School (PJDS) in Philadelphia gather in the auditorium for tefillah. Without prompting, they divide themselves quickly into small groups of 10–12 students. This is what the school calls its “Kotel minyan,” a loose approximation of the disparate ad hoc minyanim held concurrently and according to their own pace and style at the Western Wall in Jerusalem. The post-bar mitzvah boys don tefillin; the girls do not. Soon a cacophony fills the room, as students in each minyan take turns leading an abbreviated Shacharit service. Each minyan decides which tefillot it will skip, but all include portions of the service that they have been taught are mandatory.