The prime focus of this page is to shed light on the flute harmonics. As you must be aware, the flute players blow air across a hole in the instrument to produce sound. This stream of air when directed across a hole creates a vibration of air at the hole. Read on to know all about flute acoustics.
According to the flute harmonics, when the air stream across this hole, it develops a Bernoulli or siphon effect. This stimulates the air present in the typically cylindrical resonant cavity within the flute. By opening and closing holes in the body of the instrument, the flute player can change the pitch of the sound. This changes the effective length of the resonator and its parallel resonant frequency. By changing the air pressure, the flute player can also vary the pitch of a note. He can make the air in the flute to vibrate at a harmonic other than the basic frequency without opening or closing any holes.
Giving more info on the flute acoustics, a flute's volume can usually be increased by making its resonator and tone holes larger. This is the reason why a large pipe organ can be much louder than a concert flute as it contains several cubic feet of air. Similarly, a police whistle, which is also a type of flute, is very wide for its pitch. While studying the basics of flute harmonics, it should be noted that the air stream must be aimed at the correct angle and velocity, or there will be no vibration in the air contained in the flute. Transverse and end-blown flutes take more air to play and therefore require deeper breathing.
The flute can create harmonics in varying proportions or intensities, depending upon the quality called timbre or "tone color". The tone color can be customized by altering the internal shape of the bore. For producing higher harmonics, the air stream is much thinner and faster. The purpose is to give more energy to excite the air's resonance.
Head joint geometry plays a critical role in the flute acoustics performance and tone. Some of the most critical parameters include chimney length, chimney diameter, and radii or curvature of the ends of the chimney. Chimney is the hole between lip-plate and head tube. A recent study has revealed that there is no evidence of the wall material having any considerable effect on the sound color or dynamic range of the flute harmonics.