Markup (ontology) of acoustic music instruments

The descriptions and images of acoustic instruments listed here serve as background for a chapter Universal information architecture of acoustic music instruments, in the book Structuring Music through Markup Language: Designs and Architectures (Steyn 2012). Mainly instruments mentioned in the chapter are listed here, with a few additional ones.

It is proposed in this chapter that the computer modeling of acoustic music instruments can be more faithfully reproduced if algorithms are developed for the acoustic properties of each component of the instrument. The resulting description of these properties is called information architecture, which is described independently of the algorithms, but inform the design of algorithms of the important acoustic properties of acoustic music instruments.

It is further proposed that this approach to modeling would make possible the virtual modeling of any kind of acoustic instrument, such as specimens found only in museums, or from archaological digs. This will allow musicians to be able to experiment with instruments that are presently not available. It would further make possible the creation of new types of sounds, not created synthetically, but by recombinations of the components of acoustic music instruments. For example, it would be possible to use a string triggering property to initiate the soundwave, then push that wave through a saxophone bell (which is usually on the exit side), run the wave through a double reed, but perhaps with a recorder's windway, and then perhaps chase it through the pipe body of a sackbutt, attached to a violin soundbox, and exiting this virtual instrument through a French horn's flare.

Acoustic Instruments A. Air  
  B. Solids 1. Strings
2. Bars
3. Membranes
Electric Instruments    

Acoustic Instruments

The structural components of instruments are descibed, assuming that the properties of each component (ranging from dimensions and materials) have unique harmonics that build on top of a base soundwave, resulting in the unique sounds of different acoustic music instruments. Describing the structural components results in an information architecture which serves as data input for computer algorithms. It is proposed that algorithms that are designed for such architectural components will enable the creation of much truer soundwaves (true to real acoustic instruments), while also allowing for the virtual creation of totally new acoustic instruments by adding different components in different sequential orders to the virtual music instrument, as well as being able to manipulate the minute values of each component.

Acoustic music instruments can be classified into two geni: air and solids. The most commonly used air instruments are pipe-like. The most commonly used solid instruments are strings, bars and membranes.

Categorizing instruments depends on which criteria and features are used. Many instruments that were invented in the early times of human history were made of naturally occurring items (eg. bamboo, reeds, bones), while once metals had been invented, the same component structues of these "natural" instruments were mimicked when made of other materials. These newer instruments were often labeled with new names. For example, animal horns were used to create sound by blowing, and rightly called "horns". Later, metals were used to mimick such blown instruments, known as "trumpets", which were primitve compared to the modern trumpet, which now has valves. So are these variations the same instrument, or do they need different labels? For present purposes the names are not decisive, but the acoustics that depend on certain structures. From this point of view most blown instruments are based on the basic acoustic principles of the horn and flute, and most string instruments variations of an instrument that for easy referencing purposes might be called a harp - assuming that bowing was a later invention than plucking.

The finer qualities of acoustic music instruments depend on the intricate variations of the smaller structural properties of instruments. The overall structure is what gives an instrument its sound unique compared to other types of instruments. When instruments share many of the major strucural components (eg. sackbutt and trombone) it takes a fine ear to determine which instrument makes a particular sound. For an example to support the view that the major structural components determine the type of instrument, see the short video clip of the Landfill Harmonic (, which uses instruments made from junk, but still present the unique sound (or tone) quality of the type of instrument.

Links to external websites were last valid in May 2012.

A. Air

Instruments in which the air column is moved in a contained pipe-like or vessel-like cavity, and blown into this cavity either by human lungs or mechanical bellows, are known as air instruments. The most common design is in the form of a pipe or tube.

Also see pipe instruments, the Bernoulli effect, Helmholz resonator, reed.

B. Solids

Solids consist of strings, bars and membranes. This classification is far from clear, as membranes and bars might be considered as permanently tensed strings, with much more value on the width axis. And membranes with soundboxes attached (such as the drum vellum attached to the drum box) might be considered as a mixture between strings and pipes.

1. Strings

See strings, Helmholz resonator

2. Bars

3. Membranes

Electric Instruments

Electric instruments are of course not naturally acoustic instruments. They are attempts at modeling sound, and therefore some early attempts are listed here.


Steyn J (2012). Universal information architecture of acoustic music instruments. In Steyn J (ed), Structuring Music through Markup Language: Designs and Architectures. IGI.