An electronic musical instrument outputs synthesized lyrics of a song based on lyric data in accordance with operations by a user. One or more processors in electronic musical instrument generate voice synthesis data for a lyric of the song based on the lyric data for the song at a timing at which said lyric is supposed to be outputted regardless of whether or not a user operation of the operating unit is detected at said timing; when the user operation of the operating unit is detected at said timing, cause voice sound synthesized based on the generated voice synthesis data to be outputted; and when the user operation of the operating unit is not detected at said timing, cause the voice sound synthesized based on the generated voice synthesis data not to be outputted.