Let's take the Hank Williams song from the last post on the subject as a baseline for the unity of country and Western music. The song dates to 1950, and it stands at something like the end of a trend in which the two genres had grown together in popular culture. Now let's look at how that baseline point was formed. The driving force was Hollywood, whose appetite for cowboy movies through the 1930s and 1940s included a developing taste for Western music. We had singing cowboys, who started off by singing traditional Western folk songs. The Sons of the Pioneers and Roy Rogers (originally together, later separate) were probably the most famous of these, from 1933. Here's a traditional Western tune.
As cowboy movies continued to be popular through the 1930s and 1940s, the musical genre began to take on aspects of another genre very popular in the '40s: swing music. Here's the same group kicking up their heels a bit in a film from 1944.
Another band that was at the forefront of Western Swing music was Bob Wills and his Texas Playboys. I believe it's correct to ascribe the introduction of the steel guitar to them. That first happened in 1935, when the band had already included a saxophone and other instruments more commonly found in jazz and swing music.
Now here's Bing Crosby making the point about the change that had overcome the Old West even in its music.
So this is the music that Hank Williams' alter-ego was performing. It was a genre that had national attention and acclaim for a couple of decades. It remained popular through the 1950s, when Westerns were still very popular in Hollywood, and even more popular on television.
Hollywood Westerns from the '50s, though, began to move away from Western Swing and back toward traditional Western music out of a desire to use the Western movie as a vehicle to present more serious films. In Rio Grande, for example, the cavalry regimental singers return to traditional roots music in order to achieve authenticity. It is therefore ironic that the authentic Irish rebel song they picked for the Irish soldiers to sing, "The Bold Fenian Men," actually wasn't composed until the 20th century.
UPDATE: Turns out we have a highly educated and well-connected fan of Western Swing in the Hall. I petitioned Gringo for some favorites, and here's what he picked (see discussion).
Ida Red shows Bob and the Texas Playboys playing an old folk tune- or should we say fiddle tune.
Trouble in Mind shows what Bob Wills can do with a blues song. Al Striklin, my third hand connection to the Texas Playboys, is on the piano.
Home in San Antone is a movie clip with some good, swinging instrument solos.
Take Me Back to Tulsa has a rare appearance of brother Luke Wills on the vocals. Tommy Duncan did most of the vocals.This is one of Bob’s best known tunes.