Three flutes of the Akimel O'odham culture, from Figure 80, page 166 of: Frank Russell, “The Pima Indians”, Twenty-sixth Annual Report of the Bureau of American Ethnology to the Secretary of the Smithsonian Institution, 1904-1905, United States Government Printing Office, Washington, D.C., 1908, pages 3–391. The bottom flute demonstrates the use of a "cloth or ribbon" over the center of the flute to serve as a block. Russell specifically notes that the bottom-most flute "has an old pale yellow necktie tied around the middle as an ornament and to direct the air past the diaphragm."