Actor Dorian Harewood (Eightball) in Full Metal Jacket asked for more money when Kubrick inevitably needed more time on the contract. Dorian asked for more money and Kubrick was furious and killed him off — in the movie. Kubrick had him laying on the cold ground for hours and riddled him with bullets.
The original score for Kubrick’s 2001: A Space Odyssey was written by Alex North, but Kubrick didn’t like it and switched at the last minute. No one told North, who showed up at the film’s premiere only to be devastated when none of his music was used.