Abstract: An electronic musical instrument wherein a function for automatically detecting the musical performance mode is provided by the condition of a hand keyboard, a foot keyboard, and a chord type specifying circuit for one finger use, etc. so as to simplify the operation of causing a chord to be stored.

Abstract: An electronic musical instrument comprises a keyboard device on which a player plays melodies or accompaniments, a sound pitch information or data processing means for producing a sound pitch information or data specified by the operation of the keyboard device and a sound pitch information or data which is above or below the specified sound pitch information or data by a predetermined number of semitones, a sound source responsive to the sound pitch information or data from the sound pitch information or data processing means for generating the corresponding musical sound signals, and an electro-acoustic transducer means for converting the musical sound signals derived from the sound source into the corresponding acoustic signals. The clock frequency of the data processing means can be switched to a lower clock frequency during a data read-out or write-in time interval and a short time interval immediately following it.