Emergency! S04E11 - The Firehouse Four

The station (except Roy) is entering the firefighters's barbershop quartet contest. Johnny clarifies his situation with Dixie, when his problem is actually with Roy, who says it takes a lot of work, whom they will all side with him. In between practices, the firemen have to render almost-constant assistance to a man who is trying various ways to exercise while on a crash diet, and a woman OD's on sleeping pills.