Harmony as three nested alignments
Xu defines 'he' (harmony), the first and governing quality, as a chain of three fits: the string with the finger, the finger with the sound, and the sound with the intention. A failure at any link breaks the whole.
Xishan Qinkuang
5 ideas
Stillness of sound follows stillness of breath
Quietness in the music cannot be produced by playing softly or slowly as a technique. It comes from regulating the breath and settling the mind, and the calm then passes through the fingers into the tone. The audible quality of a performance is read as a direct trace of the performer's inner state, so practice has to include cultivating that state.
Blandness as depth, not deficiency
Xu elevates 'dan' (plainness, blandness) above ornament, colour, and crowd-pleasing virtuosity. He treats flavour that is withheld as more lasting than flavour that is displayed. On this view, a player who seeks the approval of vulgar ears has already lost the instrument's highest register. Restraint becomes the sign of mastery rather than a lack of skill.
Tempo qualities paired as complementary opposites
Several of the twenty-four qualities come in paired opposites: light and heavy, slow and fast, fine and grand. The player is taught to govern the balance between each pair rather than to favour one side. Speed is legitimate only when it serves that expressive intent and does not become display.
A Yushan disciple codifies qin taste
Xu Shangying was a Ming qin player in the Yushan school tradition. He wrote them partly to rebuke the popular practice of setting qin music to sung words and ornate display. The case shows a practitioner turning an oral, school-based aesthetic into an explicit taxonomy of qualities that could be learned from a text.