. >> reporter: their cover of the lum ne hit is the most viewed this year. >> we knew they were talented i would be dealing with it this early. ♪ ♪ >> reporter: the 14 and 9-year-old sisters take center stage as the youngest stars of tv's nashville. >> they're amazing. >> it is so awesome. >> really, really, happened so quick. it has been such a blessing. an overnight success thanks to a show that makes being discovered look so easy. >> i'll make you a deal. you get three songs together. i will cut the demo for you myself. >> that is amazing. ♪ just another picture to burn >> reporter: add to that, country mega stars like taylor swift fanning the flames drawing a jen ration generation of hope music city. to find out what lures them, we spent a week in nashville, meeting kids, filling casting calls, lining up, dreaming of stardom. ♪ not going nowhere >> either a rock star or degree in musical theater. >> reporter: willing to do just about anything. >> i can whistle. to sacrifice even their childhood for a long shot chance at fame and fortune. casting coach regina moore has her eye on a ne