Flutes are one of the simplest musical instruments that can be produced. They consist of a basic tube with finger holes, a sound hole and a mouthpiece, and the vibration of air across the mouthpiece or reed produces sound. Most are made out of metal or wood. The Japanese bamboo flute, also known as a shakuhachi, is an end-blown flute used to produce a variety of tones and played similarly to blowing over the end of an open bottle. The structure of the shakuhachi allows a flexible variety of tones as opposed to the specific pitches used by recorders or similar flutes.
The bamboo flute is approximately 21.65 inches (55 cm) long; its name, shakuhachi, comes from the medieval Japanese equivalent measurement. It has four finger holes on top and one on the bottom. A standard shakuhachi has a base note tuned to D just above middle C, with the other four notes as F, G, A and C. The player grips the flute with both hands and covers the finger holes with the index and ring fingers. Different finger patterns, such as covering one-third of the hole, half, or two-thirds of the hole, can all alter the sound.
Pitch variation on a bamboo flute consists of more than just finger placements; the player must also tilts his or her head up and down to change the angle of airflow. Lowering the pitch is called meri and raising it is called kari. Changing the speed of airflow alters the octave at which the shakuhachi plays. It has a range of two octaves and half of a third octave; these are known as otsu, kan and dai-kan. Attempting to produce a note too high for the flute will cause it to make a dissonant squeaking sound.
A bamboo flute has to be hand-made to produce a quality sound because each flute comes from a live stalk of bamboo and no two pieces of bamboo grow the same. Shakuhachi also have to be custom-made for their users. Longer ones have the finger holes spaced more widely and have a lower pitch.
The shakuhachi has three main styles of play. These are honkyoku, solo; sankyoku, a traditional ensemble with the shamisen, a stringed instrument and koto, a woodblock; and shinkyoku, a Western-influenced ensemble. The bamboo flute, due to its sound versatility, features frequently in orchestral film soundtracks.