The numbers on the metal bars represent the rhythm type. That is, the relationship between the strength and weakness of the beat:
Among them, 2 is the rhythm of two beats. The relationship between the strength and weakness of the sound is | strong weak | strong weak |...repeatedly. This is a 2/4 time pattern. This mode is also generally called march.
3 is a three-beat rhythm. The relationship between the strength and weakness of the sound is | strong weak weak | strong weak weak |...repeatedly. This is a 3/4 time pattern. This mode is also generally called waltz.
4 is a four-beat rhythm. The relationship between the strength and weakness of the sound is | strong, weak, next strong, weak | strong, weak, next strong, weak |...repeatedly. This is a 4/4 time signature. This mode is also generally called caroling.
6 is the rhythm of six beats. The relationship between the strength and weakness of the sound is | Strong Weak Weak Next Strong Weak Weak | Strong Weak Weak Next Strong Weak Weak |...repeatedly. This is a 6/4 or 6/8 time signature.
To put it simply, for 2/4 shots, adjust the meter ruler up to 2, for 3/4 shots, adjust the meter ruler up to 3, and for 4/4 shots, adjust the meter ruler up to 4. For this beat type expressed as a fraction, adjust it to whatever the numerator is.
Extended information:
Main functions:
1. The metronome can cultivate the concept of speed. The most basic function of a metronome is probably to determine the speed. When practicing the piano, use it to determine the accurate speed of the music being played, thereby gradually building up a keen sense of speed, which is very necessary for an excellent performer.
2. Make the performance more complete and stable, and the rhythm more even. Use a metronome to practice slowly and patiently, and gradually adjust the movement. Unknowingly, the speed of the music increases, and the playing speed and rhythm are smooth and even.
3. Focus your attention and improve the efficiency of piano practice. When some young children practice the piano, they often play while playing. It takes a long time to play such a short piece of music. Even older students or adults who practice for a long time will be distracted due to paralysis. Using a metronome can solve this problem. Its "click" sound reminds the practitioner not to fall behind for a moment and wait for the designated time. After completing the practice section, feel free to relax.
Reference materials:
Baidu Encyclopedia--Metronome