Various tribes located in the Xingu River area practice a ritual called the "Ritual of the Flutes."  The actual ritual varies from tribe to tribe, but the instruments are the same: giant flutes that measure up to three meters in length.  Although men exclusively play these large flutes, females are often involved in the ritual.  Most commonly a girl will accompany each flute player by placing her hand on his shoulder and will be led by him during the ritual.  Sometimes the girl will have her hair cover her eyes, preventing her from seeing, and the ritual becomes a rite of passage for the pubescent girl.  Interestingly, no one tribe has a monopoly on this flute ritual and many different tribes have adopted its practice despite speaking different languages and having different ethnic backgrounds.