Post was hired along with Stephen Geyer to write the theme tune for a new TV series dubbed The Greatest American Hero , about a high school teacher who comes into possession of a superhero outfit , and Scarbury was chosen to record it . Post was hired along with Stephen Geyer to write the theme tune for a new TV series titled The Greatest American Hero , about an average high school teacher who comes into possession of a superhero outfit , and , as luck would have it , Scarbury was given the opportunity to record it .