Andrew left his drumsticks at the rental car business (Dramatic Irony)
After arriving late to the jazz competition, Andrew fights for Fletcher to let him play in the competition, telling him that he just has to grab his drumsticks from the car. However, the drumsticks are actually a ten-minute drive away. While we the viewers know that Andrew lied and has to go back to the rental car business, no one at the competition knows, and they wonder why he is running so late.
Fletcher knows that Andrew turned him in (Situational Irony)
After getting Fletcher fired from Shaffer, he agrees to play at a festival that Fletcher is conducting, hopeful that he can move on from their abusive teacher-student dynamic. When he takes his place at the drumset, Fletcher comes over and tells him that he knows it was Andrew who got him fired. As Fletcher takes his place at the conductor's stand, Andrew realizes that Fletcher has never been on his team, and that he invited him to play in the concert so that he could humiliate him and get revenge. This is a moment of situational irony, because it subverts Andrew's—and the viewer's—expectation about what will happen at the concert.
Ryan (Situational Irony)
Very soon after Fletcher promotes Andrew to core drummer, he introduces another drummer into Studio Band. In the moment that Andrew finally feels validated and at home in the band, his position as core drummer is compromised. Not only that, but Ryan, the new drummer, is an old peer of Andrew's and a less-talented drummer. This moment is ironic because it highlights the unpredictability of competitive jazz drumming under Fletcher, and the ways that Andrew is unable to predict how he will fare in such a competitive environment.
Andrew earns Fletcher's respect at the end (Situational Irony)
One of the sharpest ironies in the film is the ending. After having a contentious and abusive dynamic with Fletcher, Andrew finally wins his respect by going against what is expected of him at the concert. While Fletcher sets him up for public failure and humiliation, Andrew takes his failure as an opportunity to improvise and demonstrate his abilities in such a ferocious and passionate way that Fletcher cannot help but smile. Thus, while it would seem that Andrew is getting revenge on Fletcher, showing him that he cannot be humiliated or discouraged, this is exactly the response that Fletcher has wanted from one of his students all along. What seems like a moment of revenge or payback actually becomes a moment of recognition and respect.
