Abstract: An electronic musical instrument comprises a plurality of keyboards each having a plurality of keys, a control circuit for controlling a manner of tone production, and a musical tone production circuit responsive to respective depressed keys of respective keyboards. The control circuit controls the musical tone production circuit in response to operation of a switch mounted on a control panel for manually selecting one of a plurality of sets of preset parameters corresponding to a kind of a musical tone to be performed. The musical tone production circuit modifies a tone specified by a depressed key in any keyboard according to the selected switch on the control panel.

Abstract: A plurality of sets of such characteristics as the color, volume and effect of a musical tone are preset for different musical composition fashions. Desired preset characteristics are selected independently in the melody performance portion and the accompaniment performance portion by operating a corresponding melody musical composition fashion selection switch and a corresponding accompaniment musical fashion selection switch thus establishing a musical tone having a desired musical composition fashion for each portion. According to a modified embodiment, when either one of the melody and accompaniment musical composition fashion selection switches is operated, both the musical composition fashions of the melody performance portion and the accompaniment portion are established in predetermined manner.

Abstract: An electronic musical instrument comprises a musical tone production circuit responsive to a depressed key among a plurality of keys, and a control circuit for controlling tone production manner which includes a plurality of manually operated members mounted on a control panel for setting parameters that determine the tone production manner. There is also provided presetting means for presetting some of the parameters. At an initial state after the instrument is powered from a power source, the preset parameters dominate the corresponding ones of the manually set parameters, while the preset parameters can be replaced by the manually set parameters at a choice of a player after powering.

Abstract: In a touch-responsive circuit adapted for use in an electronic musical instrument provided with a keyboard, and comprising a key depression speed detector including a change-over switch, a capacitor for storing electric charge and a discharging resistor, and a controlling signal generating means including a gating transistor controlled by the key depression speed detector and another capacitor for storing electric charge through said transistor, a voltage-compensating element is connected in the key depression speed detector so as to compensate for the threshold voltage of the gating transistor thereby raising the minimum output voltage of the key depression speed detector and insuring the sound generation for the pianissimo performance.

Abstract: This invention is directed to a keyboard circuit for generating pitch determining voltage signals whose voltage values exponentially vary with respect to notes. Key switches are connected between a DC voltage source and a voltage dividing resistance network, thus making it possible to use key switches having a simpler contact construction. Nevertheless, the keyboard circuit of the invention can act as a lower or higher tone preference circuit.