WSM signed on from Nashville in 1925, owned by the National Life and Accident Insurance Company — its call letters stood for the company's slogan, "We Shield Millions." Weeks after launch it began broadcasting the barn-dance programme that became the Grand Ole Opry, and its powerful clear-channel signal at 650 AM carried country music across most of North America. More than a station, WSM is one of the foundational institutions of country music itself.
