Abstract: The electronic metronome has a baton reciprocatingly driven by a pulse-drive stepper motor powered by a varying voltage source. Drive circuitry generates and applies drive pulses to the stepper motor, each drive pulse being composed of a plurality of individual pulses having a pulse width which varies in accordance with variations of the voltage source and with the selected tempo at which the baton reciprocates. The stepper motor is thus driven at a constant torque-frequency characteristic despite fluctuations in the power source voltage and the tempo of the metronome.

Abstract: An electronic metronome has a visual indicator, a loudspeaker, and a duty time setting circuit for setting the visual time of a visual indicator corresponding to each speed of various tempos. Accordingly, it is easy for a singer, a player, etc. to precisely see the predetermined tempo by using the duty time setting circuit.

Abstract: A tuning device for musical instruments or voices comprises a visual stroboscopic displaying means which displays a light flow at a speed proportional to the difference of a tone to be tuned from the signal of the corresponding standard pitch. A standard pitch in a predetermined octave is synthesized from pulses generated by a high frequency oscillator the standard pitch and is divided into a pitch in a predetermined lower octave for comparing the tone to be tuned in the stroboscopic displaying means. The tone to be tuned is also divided into a signal of a pitch in the lower octave and it is transmitted to the stroboscopic displaying means.The stroboscopic display means compares the signal to be tuned with the standard signal, making a light-flow display by overlapping both the signals. The pitch and octave of the tone to be tuned is previously set on the device with a manual selector switch.