The ballad opera is a genre of English stage entertainment that originated in the early 18th century, and continued to develop over the following century and later. Like the earlier comédie en vaudeville and the later Singspiel, its distinguishing characteristic is the use of tunes in a popular style (either pre-existing or newly composed) with spoken dialogue. These English plays were ‘operas‘ mainly insofar as they satirized the conventions of the imported opera seria. Music critic Peter Gammond describes the ballad opera as “an important step in the emancipation of both the musical stage and the popular song.”

https://en.m.wikipedia.org/wiki/Ballad_opera