Continuity mistake: During a session in class when they were discussing marriage etc, Potter and Denham can be seen in the background leaning in their chairs against the wall. The discussion then involves them and the Teacher played by Sidney Poitier. In the scenes that follow it shows them leaning on their desk when the pair of them are talking to the teacher, and when the teacher is talking it shows them in their original posture with their chairs still tilting.
Revealing mistake: At the end when the class are having their dance, the band manage to play without any amps, speakers or mikes. We even hear keyboards, despite no-one playing any.