A horse opera, hoss opera, or oat opera is a western movie or television series that is extremely cliched or formulaic (in the manner of a soap opera). The term, which was originally coined by silent film-era Western star William S. Hart, is used variously to convey either disparagement or affection. The name "horse opera" was also derived in part from the musical sequences frequently featured in these films and TV series which depicted a cowboy singing to his horse on-screen. The term "horse opera" is quite loosely defined; it does not specify a distinct subgenre of the western (as "space opera" does with regard to the science fiction genre).
References
Horse opera Wikipedia(Text) CC BY-SA