Mapp was born in Social Circle, Walton County, Georgia. He relocated in 1922 to Newton County, where he met the guitar player Curley Weaver. Mapp was noted in Newton County as a harmonica virtuoso with a unique style, who often performed for tips on the street. In 1925 Weaver and Mapp left for Atlanta. The twosome played at country dances. Weaver then formed a group with Mapp, Barbecue Bob, and Bob's brother Charlie Hicks and continued to play locally. In 1929, billed as the Georgia Cotton Pickers, they recorded for the Atlanta-based QRS label. Mapp also cut one solo track, "Riding the Blinds", the same year. None of the songs sold well.
In November 1931, Mapp was found stabbed on an Atlanta street corner. His death certificate recorded that the brachial artery in his left arm had been severed. It gave his age as twenty. No one was charged with his murder. The certificate also noted that he was a musician; it was unusual at the time for a coroner to acknowledge such employment.
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By Eugene Chadbourne
This fine blues harmonica man played and recorded with two legendary guitar pickers and singers, Blind Willie McTell and Barbecue Bob, also known as Robert Hicks. Thus, Mapp has a firm membership in the elite circle of country blues harmonica players, but those whose curiosity extends toward the morbid will be interested to know of his membership in a decidedly more peculiar category of blues artists. And to put it politely, that would be those blues artists whose careers would have gone on much longer had they not been murdered. Mapp was first heard of as a player around the age of 12, when he is said to have hooked up with the amazing guitarist Curley Weaver, the two of them playing at country dances and parties, sometimes as a duo and sometimes in tandem with Barbecue Bob and his brother Charlie Hicks. His style was said to be instantly recognizable and the story is told of two old-timers from the area who instantly picked out Mapp from his solo recording after not having heard him play for 40 years; neither man had any idea that he had ever recorded. Mapp more often played on the streets for tips than in the studio, but he did get in the studio thanks to Barbecue Bob in 1929 as part of the group the Georgia Cotton Pickers. He also recorded one solo, the extremely rare "Riding the Blinds," cut for the QRS label in 1929. Mapp wound up playing backup harp on quite a few sides cut with various artists for this Atlanta-based label, but distribution was minimal and many of these records disappeared off the face of the earth. His boss Hicks died just a month before Mapp did. The harmonica player was found stabbed on the corner of Houston and Butler in Atlanta. The brachial artery of his left arm had been severed, according to the death certificate; no one was ever arrested for this murder. The fact that his occupation was listed as musician on the death certificate is given as proof of his high level of career accomplishment, as it would not have been a common thing for the coroner's office to show even this much respect for a bluesman. There is some question about whether he was actually as young as 20 when he died, the possibility being that the year normally attributed to his birth might be wrong. Of re-released material featuring Mapp, the best choice is Georgia Blues on the Document label, which features both his solo piece as well as his accompaniment on nearly half the songs.