Whether you are referring to North American Indian flutes or Indian flutes from India, you are referring to a flute made from natural materials that is used for playing music endemic to that particular culture.
The flutes carved by North American Indians are hard to find these days. Because of loopholes in American laws, anyone, anywhere can make a “Native American flute” if it is a wooden duct flute with a block whistle embouchure. The few Native Americans who carve such flutes cannot compete with those that are produced in large numbers in other parts of the world. The only way to make sure that a flute is an actual flute from a Native American is to look for the IACA (Indian Arts and Crafts Association) seal on the seller’s website or sales venue.
Of Native American flutes, the plains flute is the most common. They are also called “duct flutes” and “block flutes.” These use an external block for making the whistle. There are usually six open finger holes. Covering or uncovering the holes in the correct order will effectively “shorten” the length of the hollow sound chamber, producing a scale. These instruments used to be made of wood like sumac, or bone that was hollowed out with a 5/8 inch bore throughout. The finger holes were originally burnt through the body of the flute.
Flutes from India, on the other hand, are made from bamboo. The ones used for classical music are transverse flutes, and they are basically a length of bamboo with holes cut in it. The two main types of these flutes are “bansuri” and “venu.”
The bansuri is used in Northern India and has either six or seven fingering holes. The seventh hole is used to correct pitch in the upper registers. Though the bansuri used to be played in folk music only, it is now used in Hindustani classical and other genres. The bansuri has great religious and cultural significance among Hindus because it is associated with Lord Krishna.
The venu is the flute from southern India, and it usually has eight holes. It is used in every variety of south Indian music.
The flute is one of the most ancient instruments. Since it is a reedless instrument, it can be made very simply from hollowed out tubes, whether they be of metal, plastic, glass, bamboo, wood, or bone. Many archeological studies have found variations on the flute in many ancient cultures. Two that are still used today by the same cultures are the Indian flutes, whether Native American Indians or Indians from the country of India.