An ensemble game system for executing an ensemble game comprises a plurality of game apparatuses 10a through 10c communicable to each other. Each of the game apparatuses 10a through 10c outputs a sound of an own part in accordance with a play operation by the player during a first play period, and also transmits play data (rehearsal data) for specifying a play result of the own part during the first play period to the other game apparatuses. Play data for specifying play results of the parts other than the own part is received from the other game apparatuses and stored on a storage device. During a second play period subsequent to the first play period, each of the game apparatuses 10a through 10c outputs the sounds of the other parts using the play data of the other parts stored on the storage device, while outputting a sound of the own part in accordance with a play operation by the player.