Filmmaker Edgar Wright's new music documentary “The Sparks Brothers” celebrates two musicians whose work he loves. Ron and Russell Mael are brothers who make up the band Sparks, and they’re a pair of complete originals. Wright is an original, too. His hit movie “Baby Driver” and upcoming thriller “Last Night in Soho” are based on ideas he made up. And he can’t help but wonder why movie studios aren’t willing to take a few more chances on fresh ideas.