In the 1920s the average American worker earned about $700 a year. Ralph Peer was pulling down $1 million. This deep dive tells the story of the invisible architect who discovered the foundational DNA of country, blues and R&B, from supervising Mamie Smith's Crazy Blues in 1920 to the Bristol Sessions of 1927, and who invented the financial machinery of the modern music business along the way.

We explore the physics of acoustic-era recording, why Peer packed the equipment onto a train to Atlanta in 1923, and the counteroffer he made when Victor denied him a raise: one cent per record side sold, split with the artists. Then we follow his Southern Music Publishing empire through the 1940 ASCAP versus BMI radio war, the rock and roll era, and his unlikely final act as a prize-winning camellia breeder.

• Recording Fiddlin' John Car ...