The Interstate cuts a sunken swathe right through the heart of Nashville, the gleaming skyscrapers of the city telling of its recently gained reputation as an economic powerhouse. Giant companies such as AT&T, FedEx, Nissan and Bridgestone have all set up major bases here as Nashville grows in confidence and influence, commerce clearly adding another string to its bow. Or maybe another string to its guitar. It may have made that move, but as we walk down Broadway (aka Honky Tonk Highway) for the first time there’s absolutely no mistaking the fact that Music City is still Music City, not only another site of huge musical origins and influence but…