First Book of Jazz by Langston Hughes, 1955. It covers the musical context of jazz in brief chapters like African Drums, Old New Orleans, Work Songs, The Blues, and Ragtime and discusses the mechanics of jazz including improvisation, syncopation, percussion, rhythm, blue notes, tone color, harmony and riffs. Through it all runs the life and career of Louis Armstrong, whose story, Hughes states “is almost the whole story of orchestral jazz in America". (From an article by Josh Jones found on openculture.com.)