Regional Mexican is Mexico's version of country music. It includes a number of different subgenres, depending on where they originated, and in what regions they are popular. One specific song style, the ranchera, found its origins in the Mexican countryside and was first popularized with mariachi, and has since also become popular with banda, norteño, Duranguense and other regional Mexican styles. The corrido, a different song style with a similar history, is also performed in many different regional styles. Other song styles performed in regional Mexican music include ballads, cumbias, boleros, among others. American country music is also popular in Mexico, but most prominently in the northern regions of the country, where a number of artists perform the genre while singing in Spanish. Tejano (also known as "tex-mex" in English) is popular in Spanish-speaking areas of the United States, particularly in and near Texas, and in northeastern areas of Mexico.
By the end of World War II, "mountaineer" string band music known as bluegrass had emerged when Bill Monroe joined with Lester Flatt and Earl Scruggs, introduced by Roy Acuff at the Grand Ole Opry. That was the ordination of bluegrass music and how Bill Monroe became to be known as the "Father of Country Music." Gospel music, too, remained a popular component of bluegrass and other sorts of country music. Red Foley, the biggest country star following World War II, had one of the first million-selling gospel hits ("Peace in the Valley") and also sang boogie, blues and rockabilly. In the post-war period, country music was called "folk" in the trades, and "hillbilly" within the industry. In 1944, The Billboard replaced the term "hillbilly" with "folk songs and blues," and switched to "country" or "country and Western" in 1949. https://www.youtube.com/watch?v=hyNAvdnZ5Ec