Wittner Quartz Metronome MT50. Wittner s most popular quartz metronome just got better. This metronome now comes with a better speaker with bigger sound. This allows the metronome to be used even with piano. This metronome features large dial for tempo selection from 40 to 208 beats/min (the dial accurately clicks into position). Choose from LIGHT only or combination of LIGHT and SOUND indicators. A440 tone generation for tuning.