Rhythm game, or rhythm action, is a genre of music-themed action video games. Games in the genre primarily focus either on dancing or simulating the playing of musical instruments. Players must press buttons at a precise time corresponding to a sequence dictated by the game. Doing so will cause the game's protagonist or avatar to dance or play their instrument correctly, thus achieving a greater score. Many rhythm games include multiplayer modes in which players compete for the highest score or cooperate to simulate a band playing together. While conventional control pads may be used as input devices, rhythm games often feature novel devices which emulate musical instruments. Dancing games sometimes require the player to physically dance on a mat, with pressure-sensitive pads acting as the input device.

The 1996 title PaRappa the Rapper has been deemed the first influential rhythm game, whose basic template forms the core of subsequent games in the genre. In 1997, Konami's Beatmania sparked an emergent market for rhythm games in Japan. The company's music division, Bemani, released a number of music games over the next several years. The most successful of these was dance mat game Dance Dance Revolution, which was also the only one to achieve large-scale success outside of Japan. Imitators of the game began to flood the genre, until it was revitalized by Harmonix's Guitar Hero. The game was inspired by similar, earlier Japanese games, but Harmonix added rock music aimed at a Western audience. The success of the game revived the genre and spawned two hugely successful franchises in Guitar Hero and the later Rock Band. The success of both expanded the console video game market and its demographics, as well as providing a new source of revenue for artists whose music appeared on the soundtracks. By 2008, rhythm games were considered to be one of the most popular video game genres, behind other action games. However, saturation of the market in 2009 by numerous spin-offs from the core titles led to a nearly 50% drop in revenue for music game published, causing them to scale-back plans for further expansion in 2010.