Dan + Shay, Darius Rucker, Rascal Flatts, Martina McBride, Drake White, Sara Evans and Lady Antebellum will take part in a special outdoor CMT Crossroads featuring Earth, Wind & Fire. Some of Earth, Wind & Fire’s biggest hits—such as “September,” “Let’s Groove” and “Shining Star”—will get a country twist as a bevy of country stars…