Opéra-comique
In Paris there is a theatre called the Opéra-Comique where these operas were performed.  Although “opéra comique” means “comic opera” it is not necessarily comedy.  Bizet’s opera Carmen is probably the most famous opéra comique, and it is a tragedy. By the late 19th century the opéra-comique usually had no spoken dialogue.  There was music all the way through (as there is in Carmen).