Icelandic composer Johann Johannsson, widely considered among the most interesting of the current generation of film composers, died in February at the age of 48. But the Oscar-nominated composer of The Theory of Everything, Arrival and Sicario had completed more work before his death. His final score, for Mandy — Panos Cosmatos’ wild horror-revenge thriller starring Nicolas Cage — is a dark, massive, industrial-metal sound that matches the grim, violent, sometimes insane milieu of the film. I interviewed the director, his manager Tim Husom, and his agent Kevin Korn, about this last work and about the new foundation in the late composer’s name.