“Nashville” is set against the backdrop of the city’s music scene and follows the lives of country music superstars as well as the up-and-coming performers and songwriters trying to get ahead in the business. Music City can mean so many things to different people. In “Nashville,” musicians and songwriters are at the heart of the storm, driven by their own ambitions. Some are fueled by their creativity and passion for fame. Others struggle to cope with the pressures of success and are doing everything in their power to stay on top.