A very rare occurrence when a song comes on and everyone sings with it because it is so familiar.
1. Today on the bus, "Hey There Delilah" came on the radio, and everyone started singing it. It was such a High School Musical Moment.
2. Yesterday, in art class, the art teacher turned the radio on. Everyone was silent until "Rock and Roll All Night" came on, then they started singing along; it was a total High School Musical Moment.