NaYin (纳音)

NaYin (纳音) is an ancient acoustic-mystical system that assigns a poetic element to each Stem-Branch pair. While the Five Elements (五行) classify the raw energy, NaYin adds texture and imagery.

For example, the pair 庚午 (Geng-Wu) has the NaYin 路旁土 ("Roadside Earth") — suggesting earth that is travelled over, exposed, and public. 辛亥 (Xin-Hai) is 钗钏金 ("Hairpin Gold") — refined, ornamental, precious metal.

Traditional BaZi readers use NaYin for nuance and storytelling, though the core analysis relies on the Five Elements and Ten Gods.