Day 1: Missouri - Rap, Race and protest

US midterm elections are just a few weeks away. Every seat in congress and a third of the senate is up for grabs. Every day this week our North America Correspondent Aleem Maqbool will be following the so-called Blues Highway, through America’s southern states where some of the country’s most pressing election concerns are being played out - and will look at how those issues are being reflected in the music of today. He starts in St Louis, where this weekend American flags were burned, in the continuing outfall from the killing of the black teenager, Michael Brown…..