John Clark on Instagram: "John Belushi and Dan Aykroyd created the characters of Jake and Elwood Blues on Saturday Night Live. The Blues Brothers went onto recording an album in 1978. Briefcase Full of Blues became a hit. The next step for ‘Joliet’ Jake and Elwood was a feature film. Aykroyd wrote a mammoth screenplay, which director John Landis edited down to a manageable story that could be filmed. Aykroyd demanded citing soul and R&B stars in the film. James Brown, Cab Calloway, Ray Charles,