Click Here and Here
for cpmments on gospel barbershop quartets that were written by blind will and posted on Mudcat's "Gospel music is Gaelic" thread.

And here is an excerpt from an online article on the African American origin of the barbershop quartet style of singing:

"The African-American origins theory is not new. Several of our early Society members and recent historians have made the assertion, or at least suggested an African-American influence upon barbershop harmony. But it was a non-Barbershopper, Lynn Abbott, who in the Fall 1992 issue of American Music published, "'Play That Barber Shop Chord': A Case for the African-American Origin of Barbershop Harmony," presented the most thoroughly documented exploration into the roots of barbershop to appear up to that time. In that writing, Abbott draws from rare turn-of-the-twentieth-century articles, passages from books long out of print, and reminiscences of early quartet singing by African-American musicians, including Jelly Roll Morton and Louis Armstrong, to argue that barbershop music is indeed a product of the African-American musical tradition.

Among Abbott's recreational quartets, W.C. Handy, for example, offers a memory that is quite telling of the racial origins of barbershop music. Before he became famous as a composer and band leader, Handy sang tenor in a pickup quartet who, he recalls, "often serenaded their sweethearts with love songs; the young white bloods overheard, and took to hiring them to serenade the white girls." The Mills Brothers learned to harmonize in their father's barber shop in Piqua, Ohio, and several well known black gospel quartets were founded in neighborhood barber shops, among them the New Orleans Humming Four, the Southern Stars and the Golden Gate Jubilee Quartette.

Early musicians associated barbershop music with blacks ...
Among Abbott's findings are specific early musical referecnes that suggest that barbershop was once acknowledged as African-American music...

Finally, the earliest known references to the term "barbershop," as it refers to a particular chord or brand of harmony, link it with African-American society. As early as 1900, an African-American commentator with the self-imposed moniker "Tom the Tattler" accuses barbershop quartet singers of "stunting the growth of `legitimate,' musically literate black quartets in vaudeville." The 1910 song "Play That Barber Shop Chord," which before Abbott's discovery of the Tattler's commentary was considered the earliest reference to the term "barbershop," also associates the genre with African-American society..."

-snip-

Source: The historical roots of barbershop harmony