Although Gay wrote numerous poems and plays, his ballad opera The Beggar's Opera was certainly his greatest success and his most important contribution. John Gay is credited with the first success of the ballad opera genre. Although many scholars believe his ballad opera was the only notable one of its kind, many scholars also believe that his opera led to the popular and successful operettas of Gilbert and Sullivan. The success of the ballad opera was immediate and Gay made a significant amount of money from the opera