In 'Jaws,' the quote 'You're gonna need a bigger boat' is a legendary realization of danger. John Williams created the ultimate movie legend of fear with just two notes. While the theme is played by the full orchestra, the core 'heartbeat' is driven by the low strings, specifically the cellos and double basses. Williams wanted a sound that was 'grinding' and 'unstoppable,' like the shark. He chose the lowest register of the cello to create a primal vibration that triggers a fight-or-flight response. When Steven Spielberg first heard the two-note theme, he thought it was a joke. However, once he heard it played by the dark voices of the cellos, he realized it was the sound of a cinematic legend. This proved that simple, low-frequency sounds can be the most terrifying, perfectly supporting a film's most tense dialogue.