After the two elders had given their allegiance to Zheng-Fu, he talked with them for a while about the various stories and the martial arts skills they used. So, he learned that the two of them were using musical instruments as martial skills as well. But it was not as potent as Zheng-Fu's skills.
Therefore, Zheng-Fu introduced and adjusted the new skills for them, along with giving them textbooks of martial skills and songs of the harp and flute that he had invented. That made them both very happy and excited to learn something new about what they loved.
“I really didn't make the wrong decision to come with you!” Elder Yan said, patting Zheng-Fu on the shoulder with a grateful expression.