Country supergroup Rascal Flatts is one of the hottest music acts in any genre, selling more than 22 million albums worldwide and scoring 14 chart-topping singles since their debut in 2000. Known for their crowd-pleasing, high-energy live shows, the Ohio-based trio’s nine albums have produced an incredible string of radio hits over the last decade and a half, including “These Days,” “Bless the Broken Road,” “What Hurts the Most,” “Take Me There” and “Here Comes Goodbye.” They’re joined at Shoreline Amphitheatre at Mountain View by up-and-coming country acts, including pop-country singer Kelsea Ballerini and Chris Lane.