Please help me i would really appricate it <3 What type of expression found in the First Amendment relates to the case?

The case:
The drama class at a middle school was preparing for their spring play in the school auditorium. One week before the performance, a parent complained to the school board that the play was inappropriate for middle school students. The school board agreed and contacted the principal, who then informed the classes that the show was canceled. Students were upset that their preparations were a waste. They believe they have the right to freedom of expression in performing the play. The school board said that students are minors and that it must approve decisions about what is presented in school by teachers or students. The students did not have time to plan a different show. A group of the students’ parents brought the case to court on their behalf, but they lost the case in state district court. The students’ parents appealed the district court’s decision to their state court of appeals. There the students and their parents won the case, but the school board appealed the decision to their state-level supreme court. The state supreme court ruled in favor of the school board. Unhappy with the state supreme court’s decision, the students’ parents are now appealing to the U. S. Supreme Court.