Chulas Fronteras is a documentary film

Documentary film

Documentary films constitute a broad category of nonfictional motion pictures intended to document some aspect of reality, primarily for the purposes of instruction or maintaining a historical record...

 from 1976 which tells the story of the norteño

Norteño (music)

Norteño , also norteña or conjunto, is a genre of Mexican music. The accordion and the bajo sexto are norteño's most characteristic instruments. The norteño genre is popular in both Mexico and the United States, especially among the Mexican community...

 or conjunto

Conjunto

Conjunto literally translates as "group," and is regionally accepted in Texas as defining a genre of music that was born out of south Texas at the end of the 19th Century, after German settlers introduced the button accordion. The bajo sexto has come to accompany the button accordion and is...

 music which is played on both sides of the Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

-Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 border. It was directed by Les Blank

Les Blank

Les Blank is an American documentary filmmaker best known for his portraits of American traditional musicians....

. A CD soundtrack of the music played in the film is also available, under the same title.

In 1993, this film was selected for preservation in the United States National Film Registry

National Film Registry

The National Film Registry is the United States National Film Preservation Board's selection of films for preservation in the Library of Congress. The Board, established by the National Film Preservation Act of 1988, was reauthorized by acts of Congress in 1992, 1996, 2005, and again in October 2008...

 by the Library of Congress

Library of Congress

The Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...

as being "culturally, historically, or aesthetically significant".