The medium itself—radio, that is—helped select a new type of performer. “Old time music, 1920s style, had been shaped in the days of no microphones, when subtlety was lost in the ambient noise of schoolrooms and front porches,” writes Bob Coltman in a provocative essay on Depression-era country music in the journal Old-Time Music . “By contrast the radio . . . was hushed, intimate . . . encouraging soft, expressive, modulated voices. . . . The old shouters and straightaway pickers began to tumble from grace,” replaced by “supple, sweet singers,” like Bradley Kincaid and the Delmore Brothers. The emblematic mid-thirties act was the Monroe Brothers, who dominated radio in the Carolinas. Voices seamlessly blending, Charlie and Bill Monroe sped through breakneck versions of mountain ballads and religious tunes, as if daring each other to play or sing a wrong note. These duets aren’t merely a forecast of Bill Monroe’s coming greatness; they are a high point in country music.

With the new professionalism came an impatience with the term hillbilly ; it was too easily ridiculed. “There is a practice among recording companies ... to call them [the mountain songs] Hilly Billy songs,” said Bradley Kincaid, a star of WLS’s “National Barn Dance,” in 1930. “When they say Hilly Billy Songs they generally mean bum songs and jail songs.”

Another image was ready to hand. Americans in the late twenties and early thirties, fed a steady diet of Western films, were cowboy-happy. Here was the answer to the hillbillies’ image problem: a ready-made rural persona that Americans found romantic and liberating. President Roosevelt’s favorite song, after all, was “Home on the Range.” “No youngster in the thirties and forties ever wanted to grow up to be a hillbilly,” writes country-music scholar Douglas Green (himself a cowboy singer) in an essay on Gene Autry, “but thousands upon thousands wanted to be cowboys.” The public tended to conflate the two personas anyway; an early silent Western by the director Tohn Ford, The Scarlet Drop , bore the working title Hill Billy . “The only real difference between a hillbilly singer and a cowboy singer,” said the national music weekly Billboard in 1944, “is a ten-gallon hat. When a hillbilly singer gets the price of said hat, he immediately steps into the cowboy class.”

The list of thirties hillbilly singers who donned ten-gallon hats is long indeed. Gene Autry, a hillbilly singer from Texas, went to Hollywood in 1934 and became the movies’ first famous singing cowboy. The same year, a group called the Kentucky Ramblers metamorphosed into the Prairie Ramblers; one of their singers, Arkansan Rubye Blevins, became Patsy Montana and warbled the million-selling “I Wanna Be a Cowboy’s Sweetheart.” The Girls of the Golden West, Dolly and Millie Good, were sisters from Illinois whose manager invented a whole biography for them, according to which they were ranch girls from Muleshoe, Texas, who’d learned to yodel by imitating coyotes.

And cowboy imagery stuck, for good. In the forties Hank Williams, an Alabama farm boy, wore Western costumes and called his band the Drifting Cowboys; in the fifties and sixties spangled cowboy suits became a country cliché; and in the seventies Waylon Jennings and Willie Nelson, calling themselves Outlaws, chose the look of nineteenth-century cattle rustlers. Today, in an absolutely unremarked bit of cultural schizophrenia, the singer Dwight Yoakam prides himself on his Kentucky coal-mining roots but wears a ten-gallon hat, chaps, and lizard-skin boots.

In the honky-tonks’ sexually charged atmosphere, old-time hill-billy music with its sentimental themes seemed out of place. Patrons wanted tougher fare, music that reflected their lives.

While Eastern entertainers dressed up as cowboys, real-life Westerners forged their own country-music sounds. A hybrid style blossomed in thirties Texas and Oklahoma: Western Swing, which blended the jazz of Southwestern black orchestras (the so-called territory bands of Count Basic, Bennie Moten, and others) with Southeastern hill-billy music. More ingredients were present: Cajun music, Mexican mariachi, New Orleans jazz, even the polkas of Texas’s German and Polish populations. Largely the creation of one man, Bob Wills, Western Swing was powered by a tension between big-band modernity and folk tradition. A vital, throbbing music, all pounding rhythms and borderline-lewd lyrics, it quickly swept the Southwest. A 1941 Billboard report has the wide-eyed tone of anthropological discovery. “Bob Wills, hillbilly band leader from Tulsa, Okla., is rated to be the most popular and wealthiest territorial [bandleader]. Wills concentrates on Oklahoma and parts of Texas. . . . His story is one of the most amazing in the band business. . . . It is often said that Wills is the most popular citizen in Oklahoma today.”