Revealing mistake: While Dr. Wentworth is driving his car trying to shut off the loud music on the radio, the dashboard shows that the car's gearshift indicator is not in "D" for "Drive."
Revealing mistake: Mel jumps over a step that he senses to be weak. The step he actually jumps onto (and collapses) has been pre-cut in a zig-zag pattern. (01:26:50)
Answer: It was a song written by Mel Brooks for the film. It's called "If You Love Me Baby, Tell Me Loud."
Bishop73