This is a glossary list of opera genres, giving alternative names.
Often specific genres of opera were commissioned by theatres or patrons (in which case the form of the work might deviate more or less from the genre norm, depending on the inclination of the composer).
[1] Opera genres have been defined in different ways, not always in terms of stylistic rules.
Some, like opera seria, refer to traditions identified by later historians,[2] and others, like Zeitoper, have been defined by their own inventors.
Original language terms are given to avoid the ambiguities that would be caused by English translations.The following cover other forms of entertainment that existed around the time of the appearance of the first operas in Italy at the end of the 16th century, which were influential in the development of the art form: