Amplitude is a 2003 rhythm game developed by Harmonix and published by Sony Computer Entertainment for the PlayStation 2. It is the sequel to Frequency (2001). The game was released in 2003 for North America on March 25 and for Europe on September 26.

Rhythm game or rhythm action is a genre of music-themed action video game that challenges a player's sense of rhythm. Games in the genre typically focus on dance or the simulated performance of musical instruments, and require players to press buttons in a sequence dictated on the screen. Many rhythm games include multiplayer modes in which players compete for the highest score or cooperate as a simulated musical ensemble. Rhythm games often feature novel game controllers shaped like musical instruments such as guitars and drums to match notes while playing songs. Certain dance-based games require the player to physically dance on a mat, with pressure-sensitive pads acting as the input device.