Our latest episode of Soundtracking sees us joined by two great friends who scooped the Camera d'Or at Cannes last year for best first feature Riley Keough and Gina Gammell co-wrote, produced and directed War Pony, which tells the overlapping stories of two boys on the Pine Ridge Reservation - brilliantly played by Jojo Bapteise Whiting and Ladainian Crazy Thunder - and comes out in cinemas in the UK and Ireland on Friday.