In each class of choir, there are students who have had choir consistently, every trimester since 7th grade, and other students who have not been consistently in the class. In high school classes, there are students in multiple grade levels.
The songs that the choir performs are not the same every year, so the instructional materials are not the same each year or trimester.
There is not a set scope and sequence like other classes. There are standards, and a sequence of instruction, but students will be in multiple places along that sequence of instruction learning together in one classroom.