Whiplash
The third act of Whiplash sees Andrew (Miles Teller) arrive at the JVC festival concert, ready to play the drums again after a coincidental reunion (and subsequent invitation) with Terence Fletcher (J.K. Simmons), whom Andrew got fired from Shaffer Conservatory of Music, although Fletcher is also the one who expelled Andrew. In an act of revenge, Fletcher attempts to humiliate Andrew on stage, but Andrew prevails, pouring himself into a drum solo that ends up impressing the man who set out to destroy him.
Scream
Although Scream successfully satirized its genre, it still managed to adhere to the "rules" of horror, including both a twist ending and a final girl. During the movie's climax, Billy Loomis (Skeet Ulrich) and Stu Macher (Matthew Lillard) tell Sidney (Neve Campbell) that they are both the killers. Loomis pressured his best friend into helping execute a murderous spree in Woodsboro out of spite for his parents' separation caused by Maureen Prescott.