CHEATING hearts . . . one last whiskey . . . murderous revenge . . . and a lonesome life. If you hear a Country and Western song, you are likely to hear one of these themes. Yet true guitar-picking, laid-back country music is quite different from the near rock veneer that it often has today. Its roots are a far cry from the best-selling format that is rejuvenating a surprised music industry. The origins of Country and Western were pure and non-commercial, as settlers throughout the United States sang home-made songs after dinner. At times, it was known as folk music, cowboy music, or even hillbilly music, and employed a variety of instruments, including fiddles. Blind guitarist Riley Puckett combined yodelling with hurried recordings to become one of the first ''stars'' of the 1920s. Yet it was the mountain-music-style of the Carter Family that set country music on its way. From there, radio stations and 1940s' Western films helped popularise the genre on a mass scale, turning Gene Autry and Roy Rogers into the icons they are today. In 1949, Billboard Magazine officially dubbed the style ''Country and Western'' music for its chart system. From there, various scenes developed, including the ''Grand Ole Opry'' scene in Nashville, which Hank Williams popularised. Bakersfield, California, become another distinct area, with Buck Owens at the forefront. At this point, its success crossed over into the pop music realm, with Patsy Cline's crystal voice and Johnny Cash's rugged balladeering gaining fans of all musical tastes. Anyone who thinks that country music is a tacky, roots-less affair is probably referring to that period during the late 1970s when genuine country artists such as Kenny Rogers, Dolly Parton and Waylon Jennings, to name but a few, sang formulaic, overly produced, schmaltzy ballads, instead of the genuine heart-felt songs which originally propelled them to success. Country music is just now recovering from that scene, and in a variety of ways. Many call it ''new country'', and it is viewed as a true renaissance for the genre. In the 1980s, such artists as Rodney Crowell and Steve Earle combined country-styled themes with a harder rock sound. Now, it is being taken to a more extreme, and altogether more successful sound, by Garth Brooks and Billy Ray Cyrus, whose Achy Breaky Heart single last year appears to be true country through his cowboy hat posture only. Meanwhile, flame-haired Reba McEntire is taking a balladeering Patsy Cline-Dolly Parton route. Parton has just turned back towards her original sound on her latest album. The list goes on with Wynona Judd, Randy Travis, Travis Tritt and Alabama all reviving the scene. Yet it is taking an even newer turns through Rosanne Cash, Dwight Yoakam and Willie Nelson. On their latest albums, all explore a ''pop'' side to country in a bid for tasteful mass acceptance. Nelson has even employed Sinead O'Connor to sing a duet with him on a Peter Gabriel penned tune. This looks to be the trend for the immediate future, with Johnny Cash signing a record deal with Rick Rubin, the producer of rockers The Cult and Mick Jagger, in a positive attempt to rejuvenate his legendary ''Man in Black'' career.