Rush E was created for the Sheet Music Boss YouTube channel as a deliberately over the top piano piece, written to sound almost unplayable with its constant fast runs and huge chords. It spread as a meme among pianists and gamers who compared its intensity to a final boss fight, with players posting attempts and animations synced to its hardest sections. The ending became especially shareable because it pushes the piece to its peak, making it a shorthand online for effort, panic and showing off extreme skill.