The blues - the big brother of jazz that spread at a slower speed yet managed to lay the groundwork for rock'n'roll, rhythm'n'blues, soul, funk and hip hop. There's a whole lot you can do with 12 bars and 3 chords as you'll realise over an hour that features early bluesmen and women from the Mississippi Delta, Chicago heads who needed to electrify to get heard in the clubs, British rockers who broke it to new global audiences and those who were 'discovered' into their seventies and beyond.