Gospel quartet singing--that male a capella style in which background singers provide a rhythmic accompaniment in harmony for the flights of the lead singers--emerged simultaneously all over the south. The Soul Stirrers came originally from Houston, the Fairfield Four from Nashville, the Golden Gate Quartet from Virginia. And of course, after World War II, with the great migration of black Americans from the rural South to the urban north, quartet singing took root on the street corners and barber shops of northern cities where it mutated into all sorts of secular forms.
But if there was a regional center at all for the early emergence of the quartet style is was Jefferson County, Alabama and the towns of Birmingham and Bessemer. Among others the region produced the Bessemer Sunset Four, The Heavenly Gospel Singers, the Kings of Harmony and the Birmingham Jubilee Singers founded by influential local quartet instructor Charles Bridges, who created a school for quartet singers in Bessemer.
But most importantly the Birmingham scene gave us Silas Steele and his Famous Blue Jay Singer, responsible as much as any group was for the popularization of a new style of quartet singing full of blues gestures and sanctified energy.
The early Birmingham style was characterized by tight, elaborate harmonies, and a cleanly enunciated lead approach that owed more to the turn of the century stage than it did to the new COGIC congregational singing. It was an approach quite deliberately built upon the sound and style of the late 19th century singing groups, both quartets and larger ensembles, founded at the early black colleges--the Fisk Jubilees and closer to home the Tuskegee Quartet and Tuskegee Institute Singers first organized by Booker T. Washington in 1884. The university groups had repertoires that consisted of pre-gospel spirituals. Their arrangements tended to mix passages of rubato performance alternating with passages of uptempo music with clearly stated rhythms. The harmonies at times can sound nearly Anglican. And the lead vocals are cleave fairly closely to the melodies--with little of the melissmas and bent notes that are hallmarks of the blues and sanctified singing.
You can hear the influence comparing this 1914 recording of the Tuskegee Institute Singers in 1914 performing the spiritual "Live a-Humble":
with Bridges' Birmingham Jubilees a decade and a half later, in 1930, singing "I Want God's Bosom To Be Mine"
Then along came Silas Steele and his Famous Blue Jay Singers. Steele founded the Blue Jays around the same time Bridges founded the Birmingham Jubilees, circa 1925, and the two groups were local rivals. Both featured the elaborate, well-arranged harmonies of the Birmingham style, but the Blue Jays had a secret weapon in Steele--not just his rich, potent baritone but also his adoption of the sanctified singing/preaching approach to lead.
Here's a number from the Blue Jays second record date, "I Declare My Mother Ought to Live Right" recorded in 1932. The contrast is clear: the background harmonies are tight and dense but the entire accompaniment is rhythmic and propulsive; the singing is full of bent notes, melissmas, and even falsetto--sanctified techniques absent from the early Birmingham style records; replacing the rubato sung sections are "breakdowns" for preaching style verses. Gospel music, as distinct from the earlier jubilee style, is in full flower, albeit with a Birmingham flavor to the harmony.
Steele's Blue Jays were the first Birmingham area group to take to the gospel highway and hit it big, at least big for the world of gospel in the 1930s--relocating first to Dallas and later to Chicago, and even recruiting former rival lead man Charles Bridges as a second lead/swing singer in the late 1940s, and becoming known in gospel circles as the "fathers of the quartet," although they hadn't so much pioneers the form as they had popularized the new, bluesy approach to it.
It was in this configuration, with two great Alabama lead singers--Steele and Bridges--that the Blue Jays cut their greatest records like this 1947 recording of "I'm Bound For Canaan Land"
While the Blue Jays would continue on into the 1960s in various configurations, it would be without Steele, who, sometime in 1948 or 1949 left the group he founded to join the Spirit of Memphis quartet, leaving the group he founded to the leadership of his one time rival on the Birmingham/Bessemer scene.