Roy Rogers, with his horse, Trigger, came to prominence in the late 1930s and early 1940s, following closely in the footsteps of singing cowboy Gene Autry. Rogers' rise to stardom transformed the "singing cowboy" from an isolated phenomenon to a recognized movie genre, and his popular success, added to Autry's, brought screen stardom in turn to Tex Ritter, Jimmy Wakely, Monte Hale, Johnny Mack Brown, and others. None of them attained the iconic status of Rogers or Autry, but all of them contributed to the mythology of the straight-shooting, clean-living hero who is also sensitive enough, in a folksy, regular-guy sort of way, to pick up a guitar and sing a song or two. The singing cowboy movie was—at least in retrospect—a natural phenomenon for the 1930s. The old West was only a generation or so removed from movie audiences, and the...