Abstract: Indicators are provided in corresponding relations to individual keyboard keys. For each of plural phrases of a given music piece, information is supplied that represents at least the highest-pitch note to the lowest note in the phrase. During performance of the music piece and on the basis of the supplied information, the indicators, for each phrase, indicates all notes within a range from the highest-pitch note to the lowest note of the phrase. Thus, the player can easily position his hands over accurate keys and thereby can comfortably carry out performance operations for each phrase. Notes to be performed in each phrase after a first note corresponding to predetermined performance timing in the phrase may be indicated in different manners (for example, by varying degrees of brightness) depending on performance timing differences, from the first note performance timing, of the notes.

Abstract: An electronic musical instrument has a voice-inputting function. Voice information and performance information are input to the instrument. The instrument stores performance data therein. Each item of performance data stored is sequentially read out. The next item of performance data is read out when it is determined that at least one of the voice information and performance information being given agrees with each item of performance data sequentially read out. The instrument includes a plurality of operating elements for performance. Display devices are provided for the operating elements, respectively. When voice input is detected, one of the display devices, corresponding to one of the plurality of operating elements, is lighted, which corresponds to the pitch name of the detected voice. When voice input ends, the light in the display device is turned off. The instrument sequentially stores the voice information being sequentially read out in another operating mode.

Abstract: An electronic musical instrument for realizing an easy selection of registration from a variety of registrations. First, a number from "1" to "10" is selected in an upper keyboard timbre select switch group, the numbers corresponding to various timbres, such as piano, organ, harpsichord, guitar, or the like respectively. Similarly, another number from "1" to "10" is selected in a rhythm selecting switch group, the numbers corresponding varies to rhythms, such as jazz, pops, mood music, children's songs, classical, or the like. According to this, a preferable registration group with respect to the music can be easily selected from a great number (i.e., 10.times.10=100) of registration groups.

Abstract: A voltage-controlled type oscillator utilizing charging and discharging of a capacitor. The oscillation frequency is made to vary in exact proportion to the control voltage by variably controlling electric charge in accordance with the control voltage during charging and discharging of the capacitor.

Abstract: A control voltage waveform generator is provided with a voltage-controlled variable resistor, a storage capacitor forming a time constant circuit together with the resistor, a plurality of voltage signal sources, and a plurality of time constant determining voltage signal sources. The voltage signal sources are sequentially coupled to the storage capacitor through the voltage-controlled variable resistor, and the time constant determining voltage signal sources are sequentially coupled to the control input of the voltage-controlled variable resistor.

Abstract: A non-linear type digital-to-analog converter comprising a decoder, control switching circuits controlled respectively by the outputs of the decoder, and an exponential function generating circuit whose analog outputs are selectively produced by the operation of the control switching circuits. An input digital representation is converted to an analog voltage output which is exponentially related to the input.

Abstract: A voltage-controlled type oscillator includes a differential amplifier constituted by a first and second transistors for establishing a current, as the collector current of the second transistor, proportional to an input control voltage, and an oscillating device for producing an oscillatory signal whose frequency is determined by that current. An element having a p-n junction is connected between the second transistor and the oscillating device and a further transistor is connected between the first transistor and a power source. A portion of the current flowing from the oscillating device is divided as a base current to the abovementioned further transistor whereby an adverse influence by the base current of the second transistor is eliminated. Thus the oscillation frequency is accurately proportional to the input control voltage.

Abstract: In a bridge circuit consisting of diodes connected in each circuit branch in a forward direction from one of a pair of opposing terminals to another with a current flowing through these diodes, impedance between a second opposing pair of terminals varies in correspondence to the magnitude of the constant current. The invention utilizes this phenomenon and provides a voltage-controlled filter employing this bridge circuit as an impedance element for determining its frequency region and thereby being capable of controlling its frequency region by voltage controlling. A primary passive low-pass filter is described as a preferred example of the invention. The invention further provides a voltage-controlled filter having the bridge circuit provided in a negative feedback loop of an amplifier in an active filter circuit and thereby being capable of controlling selectivity Q by controlling the gain of the amplifier by voltage controlling.

Abstract: A waveform converter for use with an electronic musical instrument comprises an input for receiving a sawtooth wave tone signal, an output for delivering a rectangular wave tone signal, a semiconductor active element adapted to switch the output voltage from a first to a second voltage level when the input voltage exceeds the threshold voltage level of the waveform converter, and a variable bias source coupled to the input for controlling the duty factor of the rectangular wave output tone signal. The variable bias source includes a variable D.C. voltage source and a subaudio sine wave source.

Abstract: In the inventive voltage-controlled oscillator, relationship between an input control voltage and an output oscillation frequency is made substantially linear by utilization of charging and discharging operations of a capacitor. The capacitor is charged with a constant current value of which is dependent upon the value of the control voltage, and the capacitor is being discharged when the charging voltage has reached a predetermined level. The charging level of the capacitor is variable and it drops as the oscillation frequency increases. This is achieved by providing a low-pass filter between the capacitor and a voltage source. According to this arrangement, as the frequency increases, the voltage applied to the capacitor equivalently decreases, whereby a discharging period of the capacitor is shortened and linearity in the relationship between the input control voltage and the output oscillation frequency is obtained.