Harmonix, or Harmonix Music Systems in full, is a videogame developer in Cambridge, Massachusetts. As the name might imply, they work primarily on the Rhythm Game genre. The company was founded in 1995, but it wasn't until 2001 that their first game, Frequency, was released. They are perhaps most well known for starting the Guitar Hero franchise, and the Rock Band and Dance Central franchises.
Games and franchises developed by Harmonix: