Many details in the history of American country music are more like legends than facts. Uncle Jimmy Thompson, it is said in legend, was the very first musician to perform on the Grand Ole Opry, or the series of live radio broadcasts of old-time music that eventually became known under that catchy moniker. The reality is actually more interesting, providing further detail into the powerful music of a fiddler who left behind only four short recordings as a legacy. WSM radio had already presented several different old-time performers, such as Dr. Humphrey Bate & the Possum Hunter...