Knives Out's narrative is full of twists and turns outside of the main murder mystery, and one of those is why Benoit Blanc keeps hitting the piano key when he's first introduced during the interrogation scenes. The 2019 release is a hugely successful whodunit movie that follows Benoit Blanc, a detective who is hired by an unknown person to uncover the murderer of Harlan Thrombey, who supposedly died by suicide. Given that Harlan was a wealthy murder mystery novelist, all the suspects are his family that seemingly want his estate. And what makes Benoit so successful are his extremely unorthodox practices.
Benoit's quirks are what makes Knives Out so rewatchable, but there's one that audiences didn't totally wrap their heads around. Benoit is sitting far in the background next to a piano while Detective Lieutenant Elliott and Trooper Wagner interrogate each individual family member, all of which are intercut. At a certain point in the interrogations, Benoit hits a piano key, throwing off the suspects. It's the first of many head-scratching moments in the movie, and it's never explained why he does it. Many have theorized it's an intimidation tactic or so Benoit can make himself known, but there's actually a definitive answer to why Benoit hits the piano key.
Benoit Blanc Hitting The Piano Key Is An Investigation Technique
Benoit knew the truth in Knives Out from the very start, and that's thanks to his unique investigation techniques. Benoit isn't just hitting the piano key at random times, instead, it's a way to alert Detective Elliott to ask a specific question. Before Benoit pushes the piano key, the suspect tends to be going off topic or asking too many questions themselves. That's when Benoit presses the key, and when that happens, Elliott asks every suspect the same question; which is what time did they arrive at Harlan's birthday party? It was something that Benoit, Elliott, and Wagner had planned before the interrogations took place.
Rian Johnson Included It For Pacing Purposes
While it's one of Benoit Blanc's many quirks, hitting the piano key has more than one purpose, as it was also a way for Johnson to pick up the pace of that specific sequence. The director thought that there were too many back-to-back scenes full of blocks of dialogue, which slowed the movie down, so Johnson's solution was to "throw a couple of drum hits in there that are offbeat" (via The Verge). The action was going to be a lot different, as it was originally planned that Benoit would tap the back of Elliott's chair. But the piano key has a much bigger impact.
