Flute hyperbass are other rare forms of the flute pitched two, three, and four octaves below middle C respectively. Other sizes of flutes and piccolos are used from time to time. A rarer instrument of the modern pitching system is the treble G flute. Instruments made according to an older pitch standard, used principally in wind-band music, include D piccolo, soprano flute (the primary instrument, equivalent to today's concert C flute), F alto flute, and B bass flute. The bamboo flute is an important instrument in Indian classical music, and developed independently of the Western flute. The Hindu God Lord Krishna
Flute ends of the chimney and any designed restriction in the "throat" of the instrument, such as that in the Japanese Nohkan Flute. A study in which professional flutists were blindfolded could find no significant differences between flutes made from a variety of metals. In two different sets of blind listening, no flute was correctly identified in a first listening, and in a second, only the silver flute was identified. The study concluded that there was "no evidence that the wall material has any appreciable effect on the sound color or dynamic range". In its most basic form, a flute is