Tra La La comes from Fortnite's emote system, where short dance routines are paired with licensed or original music loops that players can trigger in matches and in the lobby. Clips of the emote spread through gameplay recordings, short form video and soundboards because the hook is recognisable even without the animation. Its simple tra la la refrain works apart from the game as a shorthand for playful dancing, winning or not taking a moment seriously, which keeps it in rotation for edits.