An electronic musical interface performs the following: displaying a chord function progression of a first segment of a musical piece that is to be played by a user in a first region of a display via identifiers specifying respective chord functions; playing back an automatic accompaniment of the first segment; receiving user performance data as the user plays the musical note input device along with the playback of the automatic accompaniment; analyzing each chord contained in the obtained user performance data to determine the chord function of each chord the user played; and displaying, in a second region of the display alongside the first region, an identifier that identifies the determined chord function of the chord the user plays so that the user can determine whether the chord function of each chord the user played matches the chord function of the chord displayed in the first region.