Country blues is probably the first and most widely known sub-genre of blues. It is often known by many other names such as downhome blues, backwood blues, rural blues or folk blues. Mostly composed of acoustics such as guitars, it mixes characteristics of folk music with that of blues. This kind of music spread across the United States early on and gave rise to several regional styles.
As the musical taste of the African-American population changed towards the start of the 60s, these sub-genres gradually started moving towards soul and rhythm. The country blues made a resurgence as folk blues and its major audience turned out to be college-aged white folks. Traditional artists of the blues genre renewed their image as folk blues artists and names such as Sonny Boy Williamson II and Big Bill Broonzy became popular countrywide.
Called Ragtime or rag time, this genre peaked around the end of 1800s and in the early part of the 1900s. The defining characteristic of this genre is the ragged rhythm.
Originating alongside Blues, Jazz had its golden age around the 1920s. With several takers for this form of music the world over, it made its transition into world music stage rather quickly. While Blues stayed rooted to its original roots, Jazz however became popular world over thanks to its acceptance among African origin folks globally.