What does it mean to press the blues harmonica by semitone, whole tone and semitone? I am a novice and can't understand this book. Please introduce the differences and methods in detail.

This hole has different sound pressure. A hole that can press out three notes is a three-hole hole. I'll explain it with three holes in the piano in C. First of all, the sound pressure can reduce the normal inhalation or inhalation sound. There is usually a semitone between the inhalation sound and the inhalation sound in the hole. For example, the inspiratory sound of four holes is C, the inspiratory sound is D, and there is a sound # C. There is a semitone difference between them. At this time, we can get the sound by pressing the sound. There is a semitone difference between three tones, that is, #G A #A, and we will get the sound #A after pressing the tone semitone. If we increase the intensity, will the sound be further reduced? The answer is yes. If we increase the intensity, the sound will be further reduced and sound #G will be obtained. Of course, we'll press the #A here into a semitone. Pinch #G is called semitone, which is mainly named relative to inspiratory sound. This specific method is the same as ordinary pressing, but the strength is different. Just press the semitone gently. If you want to press the whole tone or semitone, you can increase the angle of the breath into your mouth, increase the air intake, and make the breath more concentrated ~ ~