horse opera

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A film or other theatrical work about the American West; a western.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun idiomatic A theatrical production, film, or program on radio or television depicting adventures of characters in the American Old West; a western.
• noun idiomatic, archaic An equestrian show, as in a circus.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a film about life in the western United States during the period of exploration and development