The profession of musicians was one of the complementary kind, as well as that of painters. That is, there was no need for a cultivator to learn techniques aimed at a single activity, as in the case of blacksmiths and alchemists.
What painters and musicians needed was to have at least one technique of the mental type. After this, cultivators of all kinds could create music and paintings, using this technique and their understanding of cultivation.
This thing worked differently for these two professions, but the point of the whole thing was the same. When creating music, or a painting, a particular cultivator would expose part of his understanding, which could influence other people along the same path.
But in addition to carrying lessons in their productions, musicians and painters could also encourage the cultivation of people who were in contact with their works!