The melodies played by the accompaniment mainly fall into three broad categories. The first is the aria. The arias of Peking opera can be further divided into those of the "Erhuang" and "Xipi" varieties. An example of an aria is "wawa diao", an aria in the "Xipi" style that is sung by a young Sheng to indicate heightened emotion. The second type of melody heard in Peking opera is the fixed-tune melody, or "qupai". These are instrumental tunes that serve a wider range of purposes than arias. Examples include the "Water Dragon Tune" ("shui long yin"), which generally denotes the arrival of an important person, and "Triple Thrust" ("ji san qiang"), which may signal a feast or banquet. The final type of musical accompaniment is the percussion pattern. Such patterns provide context to the music in ways similar to the fixed-tune melodies. For example, there are as many as 48 different percussion patterns that accompany stage entrances. Each one identifies the entering character by his or her individual rank and personality.