Intonation is the most basic and difficult issue for all music lovers. A well-known xiao and flute maker once said that his xiao and flute "the pitch error is less than one cent". This is not a big talk, nor is it deceitful, but because the speaker is only half-understood about the rhythm.

First of all, although the concept of the interval of a cent is clear, the producer does not know the meaning of a cent in physics. The following is a brief explanation. The lowest note of the flute should be a1, which is 440 Hz. A cent below this is 439.75 Hz, which is only 0.25 Hz below 440 Hz. If these two tones are played at the same time, it will take 4 seconds for a "beat note" to appear, and there is no such acute hearing at present. Today, the highest note d4, which is played by the flute and can be used for playing, has a frequency of 2349.32 Hz, and is one cent higher than it is 2350.68 Hz, but the difference between the two notes is 1.36 Hz. This shows that the same cent, in different ranges, the difference is not the same. If these two tones sound at the same time, there will be a beat sound in 0.74 seconds, which the human ear can hear after a little training.

Secondly, the intonation is based on the temperament system. Different temperament systems have different pitch requirements. For example, the minor second of the twelve equal temperament is 100 cents, the major second is 200 cents, and the major second of the third law of profit and loss is 203.91 cents. The minor second is not only five fifths apart, intervals It is an ancient minor semitone of 90.22 cents, and an ancient major semitone with seven fifths and an interval of 113.69. Another example is the major third, the twelve equal temperament is 400 cents, the third gain and loss temperament is 407.82 cents, and the pure temperament is 386.31 cents. As for the traditional legal system in our country, some people mistake it as "seven equal laws", and Mr. Yang Yinliu inappropriately named it "equal difference laws". There are many kinds of laws, which one should be the standard? Of course, different pieces of music have different pitch requirements: in the current situation where the twelve equal temperament is popular, the pitch requirement can be dominated by the twelve equal temperament. Here we will not talk about the inadequacies of the twelve-average temperament, but also admit that theoretically, the flute can be made to fully conform to the twelve-average temperament. But to achieve the pitch error of less than one cent, that's just an extravagant hope. The reason is simple, because in actual performance, intonation is relative.

Instruments are mastered by the player. In the process of playing, people always adjust the pitch by hearing; if the player closes his eyes and listens, the melody played must not be satisfactory. Human hearing can tolerate an error within 10 cents. As long as it does not exceed this error range, it can be determined to meet the pitch requirements.

Musical instruments are mastered by people, and the pitch of the flute sometimes varies from person to person. Sometimes we encounter the following situations: A flute A is accurate when it is played, but B is not accurate when it is played. So is the sound of this flute accurate? allow! Because the sound of the sound of the armor is accurate, it is the proof. As for B's inaccurate sound, it is because the position of B's "mouth gap" (the gap between the upper and lower lips for blowing the air) is obviously different from that of A. At this time, as long as B adjusts the position of the mouth seam, the sound of the flute will be accurate. Of course, nowadays the mouthpiece of the flute is very wide open, and it is rare that the pitch changes due to the obvious difference in the position of the mouth seam. This question involves a lot of music and acoustics issues, so I won't go into details.

It is precisely because of this problem that flute makers try to avoid obvious changes in the position of the mouth seam when tuning the sound. I sometimes make a flute or a flute for my close friend, and I try to make the mouth shape, luck and the position of the mouth seam the same as that of the other party. If you find that the sound of the flute is inaccurate, you can find a suitable position of the mouth seam (that is, a suitable amount of pipe end correction), instead of digging a large sound hole arbitrarily. If the position of the mouth seam must be moved very far, the pitch will be accurate. At this time, just dig the blow hole a little bigger, and the pitch will be improved.