The melody is Korobeiniki, a 19th-century Russian folk song about a peddler, which became world famous as the main theme of Tetris. Hirokazu Tanaka arranged it for the 1989 Game Boy version, and that bright chiptune version has stayed linked to the puzzle game ever since. As Tetris spread to consoles, phones and online play, the tune became shorthand for stacking blocks, rising speed and last-second saves. It still appears in gameplay videos, remixes and nostalgic edits because listeners recognise it instantly.