On his first solo song in two years, the rapper ushers in his new era as an independent artist Vince Staples in “Blackberry Marmalade,” screenshot via YouTube Vince Staples is back with his first new solo song in two years and it’s a dark one. Over a noise-rock beat, “Blackberry Marmalade” seems to be about modern anti-establishment views aligning with horseshoe theory, and includes the refrain “Promise me you won’t gun me down” along with references to Kanye West crashing out and Princess Diana. It also comes with a graphic, age-restricted music video co-directed by Staples and Bradley J. Calder . You can watch that below. The “Blackberry Marmalade” video is filmed in the style of a first-person shooter game. In it, the cameraperson lifts a gun in a parking lot and targets Staples, who tries and fails to disarm them, before entering a diner to stage a mass shooting.…