The Jubalaires were a gospel quartet from the forties that sang with a "rhythmic, rhyming style," which has been described as an early version of rapping. Today I learned that their 1946 song "Noah" is considered the first recorded instance of rap. (Nag on the Lake, Moss and Fog)
To say the Jubalaires were an isolated influence on rap's development in the 20th century however, would be to ignore the importance of The Watts Prophets, Rudy Ray Moore's Dolemite, The Last Poets, Pigmeat Markham, Muhammad Ali, and Moms Mabley on the genre (to say nothing of the importance of Black gospel storytelling). But undoubtedly, the manner in which they would harmonize and form a rhythmic, syncopated style of speak-singing in their verses was groundbreaking. Rapping, gospel preaching – perhaps it all comes down to a rich stew of culture, community and semantics, doesn't it?