Lou Wuchen stood by the fence by the cliff, looking at the small town at the foot of the mountain from afar. The gentle breeze blew his clothes, bringing a slight itchy and refreshing feeling. Lou Wuchen has always hated people who smoke, but for some reason he had some understanding: if he lights a cigarette at this time, it should be very comfortable, right?

"teacher."

"Xiang Guang?" Lou Wuchen turned around and looked at his student, "Didn't you go to rest?"

"It's not just me..." Xiang Guang scratched his nose, "Everyone is, everyone basically has no habit of sleeping at noon, so it's just a quarrel in the dormitory."

"Well, you will get used to it... it will be very uncomfortable if you don't sleep in the afternoon class?"

After Lou Wuchen said this, he stopped talking, and did not ask Xiang Guang's intention. He turned around and continued to look into the distance, not knowing what he was thinking.

Xiang Guang hesitated for a while, then made up his mind to take another step forward: "Teacher."

"Um?"

"Why... are you so good to us?" Xiang Guang used his eyes as if he wanted to see through the person in front of him to look at Lou Wuchen's back. "You not only saved us, but also healed us, and made so many arrangements for us not to give up our lives. I heard that the immortal said he was still running for us in the sky, and even prepared for us-Why, you are an immortal? Why do you have to do this for us?"

Lou Wuchen did not directly answer Xiang Guang's question. He let out a long sigh, as if he was spitting out a smoke ring that did not exist. Then he turned around and looked at Xiang Guang and asked, "...Xiao Guang, do you find the morning class interesting?"

Unexpected words made Xiang Guang stunned, but he nodded quickly: "It's very interesting."

“Want to know more?”

"think."

After Lou Wuchen looked at Xiang Guang's eyes seriously, he raised his head and said as if he was talking to himself: "That... that's good."

"——Teacher!" Xiang Guang looked at Lou Wuchen's departure back and shouted, "Is there anything we can do for you-"

"—Go and learn." Lou Wuchen threw down this sentence and waved his hand to walk away, "Use what I will give you to know and change the world."

————————————

The afternoon class was no longer held in the square. As the bell rang, the children walked into the large classroom notified in the morning. This classroom was a bit different from what everyone imagined. It was low inside and high outside, and rows of tables and chairs surrounded the bottom podium from outside to inside, from high to low. In the center of the podium, Lou Wuchen had already stood there early, fiddling with many strange orchestras and wooden strips on the podium.

The second ringtone rang, and Lou Wuchen stopped the movements in his hand and looked up at the children in the classroom.

One hundred and one hundred and one hundred and fourteen children rescued from Jinlu Gate, as well as Mu Yu, Mining and Zhang Zhaoqing, who were later picked up from Zhou Gaocheng, were already sitting in this wide staircase classroom. Lou Wuchen cleared his throat and amplified his voice and said, "Good afternoon, everyone, how about the lunch break?"

"Well, you can understand a little bit by looking at your expressions. It seems that you are not very adapted to naps, but it doesn't matter, you should get used to it in the future. Okay, our course this afternoon officially begins. In the morning, we talked about the school that proposed the theory of numbers in everything, and everyone also has a preliminary understanding of the theory of numbers in everything, but for them, the theory of numbers in everything is not limited to this. They believe that 'number' not only controls all tangible things, but also controls the intangible things in the world, such as... music."

Lou Wuchen gently plucked a long string on the podium and made a loud "clang" sound: "Do you know the rhythm?"

"It doesn't matter if there isn't." Lou Wuchen smiled and continued, "I just need to feel it with intuition."

That's it - everyone listen to these sounds first."

Lou Wuchen plucked several strings of different lengths in turn, and a series of string sounded like steps: "The musical sound is caused by vibration - but this is not what we are talking about today. After listening to the pronunciations just now, what do you think?"

In the afternoon, the enthusiasm and enthusiasm of the children's participation seemed to have improved greatly compared with the morning. They also understood the classroom order formulated by Lou Wuchen, and raised their hands to express their opinions:

"Teacher, these sounds are sharper than the other!"

"No, it's higher than the other! It's like climbing a mountain!"

Lou Wuchen smiled and let one child say his own opinion. Suddenly, his eyes jumped slightly and looked at a girl who was hesitating and raised her hands: "...Zhaoqing, tell me how you feel?"

"Teacher, I think the ninth tone just now... is a bit like the second one?"

As soon as the girl finished speaking, the child next to her retorted fiercely: "Nonsense! These sounds are sharper than the other, and the ninth and second ones are so far behind, how can they be like it?"

This sentence seemed to have caused a chain reaction from other children. Faced with fierce opposition, the girl was at a loss. At this time, Lou Wuchen waved his hand and stopped the discussion that was about to rise: "Okay, everyone, calm down!"

Lou Wuchen gave Zhang Zhaoqing an approving look, and then continued: "We said this in the morning. The best way to verify whether a statement is correct or not is-"

“Try it!”

"Yes." Lou Wuchen nodded and pressed the previous strings again, "Let's listen again."

A clanging voice shot out from the string again, and this time the children all raised their ears, afraid that they would miss something.

"...Huh?" A child began to exclaim softly.

"It seems to be really..."

“—Is it a feeling of likeness?”

Listening to the rustling discussions of the children, Lou Wuchen did not speak, but smiled and called it again.

"Really true, it's true!"

"It's not just these two! The first one is also very similar to the eighth one! It's just to be taller!"

After the children almost reached a common conclusion, Lou Wuchen clapped his hands and attracted the attention of the children: "Okay, have you all heard it?"

"I heard it!"

"Is Zhaoqing right?"

"right!"

Lou Wuchen nodded vigorously: "That's right, Zhaoqing is the first among all of us to discover this. She is the little philosopher among us! Let's give her applause!"

The girl suddenly panicked, as if the applause and praise from the crowd made her uncomfortable than the objection just now. Her face was red and she didn't even know where to sway her hands. Seeing that the morning gloomy look in her eyes disappeared a lot in the panic, Lou Wuchen nodded slightly and continued to say: "As Zhao Qing discovered, there is a special similarity between these sounds. Is this also because of the influence of 'number'? Let's take a look."

"These two notes, these two notes, and...these two notes." Lou Wuchen plucked several strings again and then removed them. "They are several notes similar to each other. Let's see if there is anything special between the strings that emit them."

Lou Wuchen grouped these strings in two groups, and each group folded the long one and the short one together: "What did you find when you see?"

The children looked at the three strings on Lou Wuchen's hands that were each in a good way: "All of them are... exactly half?!"

"What half, the teacher said in the morning, it's one-half!"

Lou Wuchen reinstalled several strings back on the shelf and flicked them gently: "

Yes, when the length of the string is doubled, the musical sounds that are made by the skeleton are similar to the original length, so we can give them the same name - this is the basis for us to form music."

"Of course, just one of the same notes cannot form music. We need a set of different notes that are well-sounding to compose good songs. Regarding how to find these best sounds, you can come down and try them yourself. Here I will talk about a method first."

As Lou Wuchen said, he took out six strings as long as he was, put them together for the children to see, and fixed one of them.

"We still need to use our 'number'." Lou Wuchen plucked the fixed string, then took another one and folded it in half and fixed it, and then fixed it. "These two notes are the same homophones we just discovered, and next, we need to find other notes that are nicely matched with them."

Lou Wuchen drew four scales between the two strings, and then picked up another empty string.

"We first split the string into three sections, cut off one of the sections and keep two sections, which means two-thirds of what we talked about in the morning." Lou Wuchen cut the string as he said, and then picked up another string to compare with it. "Then, we divided the cut string into three sections again, and this time, add one-third of it."

The children seemed to be a little dizzy when they heard it, but this time Lou Wuchen did not explain it again. Instead, he picked up the two strings and repeated the steps, and finally got four strings of varying lengths. Lou Wuchen put them in the four scales between the first two strings according to their lengths, and then plucked them one by one.

A melodious sound of piano floated in the classroom. It was a very simple and bright tone, but it was very pleasant and soft, like a wisp of breeze carrying the fragrance of flowers in the early spring morning, or like a bit of sunshine through the shade of trees in midsummer afternoon, like a mother's embrace, with a comfortable and warm atmosphere.

The children couldn't help but indulge in the sound of the piano, squinting their eyes as comfortable as small cats.

As the continuous sound of the piano, many children squinted their eyes and fell asleep like this. Lou Wuchen didn't seem to be offended, and he still played this simple song with a smile.

I don't know how long it took, Xiang Guang woke up from a deep sleep. He realized that he had not slept so well for a long time. Some things that had been suppressed for a long time seemed to have dissipated and released in a short sleep just now, and he felt a wonderful feeling of being reborn.

Obviously, he was not the only one who felt this way. The other children who gradually woke up were also surprised by their spiritual changes and started to talk softly.

At this time, Lou Wuchen's voice attracted everyone's attention again:

"Did everyone feel it? Although there is no specific shape, it still has the power to touch people's hearts. This is the charm of music. To obtain this charm, we need to, as I said just now, on the basis of our benchmark tone, first two-thirds, then four-thirds, then two-thirds, and four-thirds - this is the so-called three-point profit and loss method, or the five-degree law of mutual generation. Through this method, we get five notes, which is the basis for us to play music - of course there are other methods, which we must talk about in future courses."

Speaking of this, Lou Wuchen picked up the wooden strips and long tubes on the side and demonstrated them: "...The principles of these are the same. Okay, today's music course ends here, and the next is the time for the manual course. The content of the manual course is-"

"Everyone can use these materials and tools at will..." Lou Wuchen pointed to the other side of the podium, "Based on what I just said, make one--"

"Your instrument is yours!"
Chapter completed!