Musiknerd

Aerophone

Table of contents

What are aerophones?

Aerophone, a term from the Greek, is made up of the words “air” (ἀήρ) and “sound ” (φωνή), literally “air sound”. This term is used in the

Hornbostel-Sachs system

 of 1914 for all musical instruments whose sound is produced by direct vibration of the air.

There are basically two main groups in this classification: On the one hand the (actual)

wind instruments

in which the vibrating air is confined within the instrument, and the free aerophones, in which the vibrating air is not confined by the instrument.

Further categorization is based on the type of sound production and is carried out at the next higher level according to the scheme of

Erich Moritz von Hornbostel

 and

Curt Sachs

 scheme.

The classification of aerophones according to sound production at a glance

Distraction aerophones

The air flowing past is divided and changed in such a way that sound is generated. In the case of free deflection aerophones, the oscillation caused by air refraction is not limited by an instrument body. This includes the real whip.

Interrupt aerophones

Interrupter aerophones interrupt the air flow at regular intervals and thus produce a sound.

Most interrupting aerophones are self-sounding, i.e. the airflow itself moves the element that interrupts the airflow at regular intervals. These include the reed aerophones: on instruments with a reed, the airflow is regularly interrupted by the vibrations of the reed. There are reed aerophones with a percussive reed, the percussive reed instruments, e.g.

accordion

harmonica and mouth organ. Mirlitones, on the other hand, in which the flowing air causes a membrane to vibrate, belong to the category of membranophones.

membranophones

.

In the case of non-self-sounding interrupting aerophones, the interrupting element is not moved by the air flow itself. These include the whirring wood, the whirrer and the siren.

Explosive aerophones

The air is compressed once here. The children’s toy firecracker is one example. The crack of a whip is also caused by the compression of the air at the end of the belt.

Wind instruments

The classification of wind instruments is based on the Hornbostel-Sachs system and is divided into woodwind instruments, brass instruments and reed instruments according to the type of sound production:

Reed instruments

Wind instruments can be divided into different categories, with the reed instruments forming a large group. With

flutes

 the airflow is directed over an edge that divides and changes the airflow to produce the sound. This edge can be the side blowing hole on the transverse flute or the front edge of the tube on rim-blown flutes such as the pan flute. The recorder, on the other hand, uses labial pipes with a fixed blowing edge in the air stream.

Reed instruments

Another group is formed by the reed instruments, in which either a simple reed (reed), as in the saxophone and the

clarinet

or a double reed (counter-reed), as on the oboe.

oboe

 and the

bassoon

is used. Brass instruments include trumpets, which are also known as lip horns. Here, the player’s lips cause the airflow to vibrate and interrupt it again and again, resulting in a characteristic sound. Examples are the cornett and the

trumpet

.

Membranopipes

Membranopipes, in which a membrane interrupts the air flow, form a special group. When the air pressure is increased, this membrane periodically allows air to escape through an opening which it keeps closed when at rest. Interestingly, the “sucked trumpets”, which produce sound by sucking in air, also belong to the group of trumpet instruments, although they differ in shape from conventional trumpets. This special classification of diaphragm pipes and sucket trumpets is not included in the original Hornbostel-Sachs classification.

How is sound produced in aerophones?

In an aerophone, an “air ringer”, a sound is produced when the flow of air passing by is broken or deflected at the edge of a cavity.

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other musical instruments