at 3:33 minutes into the clip the camera zooms out from a close-up of the main character's face. The main keyboard riff to the song is heard. The song remains in the background for the duration of the sequence where a fight breaks and the main character proceed to beat another man with the gun. while he is being dragged out of the room the song's volume increases. I know this keyboard riff. It's been sampled in a few popular rap songs. What is the song's name and who performed it? Thanks!