Bunk Johnson was one of the top trumpeters in New Orleans between roughly 1905 and 1915, a formally trained prodigy who could sight-read and improvise, played with the Superior Orchestra and the Eagle Band, and studied under Adam Olivier. He was also a notoriously unreliable narrator of his own life, aging himself up a full decade to 1879 and claiming to be a regular member of Buddy Bolden's band. When he skipped a Mardi Gras parade in 1915, the furious krewe threatened him with violence and he fled the city, eventually settling in New Iberia, Louisiana, where he worked in rice mills and for the public school system. A 1931 dance-hall brawl in Rayne cost him his trumpet and his front teeth, and for more than a decade the musician effectively disappeared.

Then, in the late 1930s, writers researching a pioneering book on early jazz history ke ...