In the Jiuzhou continent, musical temperament is the Dao; the Tianyin Immortal Sect and the Youming Demonic Palace are like fire and water. Gate-guarding zither boy Chu Lingfeng accidentally awakens the Jiutian Wanlai Tianyin System, where a broken-string old wooden zither conceals heavenly Dao rules. Keeping a low profile on ordinary days, facing a massive demonic invasion, he plays the zither in a crisis, using clear sounds of the nine heavens to purify demonic obstacles, dimensionally crushing the demon lord Dugu Sha. After achieving success, he cares not for his exalted position, floating far away into seclusion, interpreting the immortal hero legend of great sound escaping the voice.