Harrison Stephens was a journalist who was also a jazz guitarist. He was influenced by the legendary George Van Eps, who had played with big-name bands and on dozens of records and soundtracks, and was perhaps best-known as the "Father of the Seven-String Guitar". Stephens set out to write a biography of Mr. Van Eps, and in the late 1980s and early '90s, the two met every Thursday for a couple of years and had conversations about Van Eps's remarkable...