When a jet of air is directed across one of the open ends at the appropriate speed, pulses of air set up a standing wave within the pipe. Some of the energy from the standing wave escapes and propagates to the ear, where it is perceived as sound. Holes in the side of the flute can be opened or closed by the player’s fingers, which changes the effective length of the pipe and the frequency of the notes that can be played.
A flute with all the tone holes closed has a long column of air, open at both ends. When the flute is played, sound waves travel up and down the flute, producing a standing wave. The air column in the flute resonates at particular frequencies—these different modes determine the notes that are possible.
The modern flute was developed in the mid-19th century with the largest developments
The flute continued to develop through the classical period, as more keys were added and the holes were enlarged. Makers at this time generally sought more volume, a ‘stronger tone’ and greater uniformity of timbre among different notes. On a classical flute, fewer cross finger- ings are used, and are necessary only in the third octave of the instrument.
Most flutes of the baroque and classical periods play a natural major scale based on the note D4. Some classical flutes have keys for the notes C4 and C♯4, and some are designed to play in different keys (such as B♭ or E). The piccolo is a small flute that generally plays an octave
Boehm redesigned the flute bore, making it mostly cylindrical with a diameter of 19mm, and tapering the bore to around 17mm at the cork. Boehm also aimed to place the holes at their ‘acoustically correct’ positions, and developed a system of keys and clutches that allows the player to play most of the notes in the equal chromatic scale with no cross fingerings. The holes on a modern flute are larger than those on a