Ahead of Thursday's show to decide the best album of the year, this documentary previews the shortlisted artists for 2017, hearing from musicians from the vanguard of grime, performance poetry and guitar rock. The 12 shortlisted acts are Alt-J, Blossoms, Dinosaur, Ed Sheeran, Glass Animals, J Hus, Kate Tempest, Loyle Carner, Sampha, Stormzy, the Big Moon and The xx.