On a freezing Chicago morning in the late 1960s, a man in a transit uniform climbed into the driver's seat of a city bus while, thousands of miles away, a young David Bowie was recording one of his songs. William "Billy Boy" Arnold wrote "I Wish You Would" and "I Ain't Got You," played the driving harmonica on Bo Diddley's "I'm a Man," and helped lay the sonic blueprint of electric blues and rock and roll, then spent years driving a bus and working as an Illinois parole officer. In this deep dive we trace a life that maps the gap between cultural influence and economic reality for Black blues artists in the mid-20th century.

We begin in a South Side household of 16 children around 1935, where a harmonica was the one instrument a kid could afford and carry into a private sonic world, and follow the teenage Arnold to informal lessons from Joh ...