Whistles and rasps are often included in Native American music. Whistles are usually made of bone and have been around for thousands of years; bone whistles discovered in northeastern Arizona came from the Basketmaker period (300 B.C. to 300 A.D.) [source: Cedar Mesa]. The eagle-bone whistle is the most common type of bone whistle, and other American Indian whistles were crafted from antlers, wood and the bones of other animals.
Rasps are notched sticks that make sounds when you scrape another stick against its notches. You can also place the rasp against the head of a drum to add resonance to the tone. The Utes call these instruments bear growlers because they use them to imitate the voice of the bear. The Hopi use rasps for their Turtle Dance; still other American Indians use its sound to imitate a frog croaking for rain.
While whistles and rasps create interesting sound effects, that's not their main purpose. Instead, their sounds are used to enhance a piece's symbolism, drawing on the materials from which the whistle or rasp was made, plus the song's purpose. For example, an eagle-bone whistle might be played during a tribe's Sun Dance to invoke the strength of the mighty bird [source: Suing].