YouTube features hundreds of videos of Southern gospel quartets, including the Countrymen, Statesmen, Blackwood Gospel Quartet, Overtones Gospel Quartet and the Cavalier Quartet. Other gospel quartets on the site include the Southern Gospel Quartet, the Cathedral Quartet, the Crimson River Quartet, Canton Junction and the Blakey Quartet.
Southern gospel music has been regarded as a distinct musical genre since 1910, when a professional quartet was formed to sell songbooks for the James D. Vaughan Music Publishing Co. However, the style is believed to have begun decades earlier with the music of Charles Davis Tillman and others, according to the website of the Christian radio station KKGM.
Southern gospel is often called “quartet music” because the genre originally featured all-male quartets. Early Southern gospel quartets performed acapella or were accompanied by a piano or guitar. The Speer Family, Smith’s Sacred Singers, the Stamps Quartet, the Blackwood Family and other Southern gospel groups became increasingly popular from the 1920s to the 1950s.
In his book "Close Harmony: A History of Southern Gospel," author James R. Goff Jr., argues Southern gospel can be listed along with jazz, blues and country as a fourth genre of American grassroots music. Today, Southern gospel features styles ranging from traditional four-part harmony to blends of country, bluegrass and gospel.