Hornbostel-Sachs

The Hornbostel-Sachs is a system of musical instrument classification created in the 19th century by Erich Moritz von Hornbostel and Curt Sachs. It is made up of 4 top levels of classification with over 300 sub-categories that attempts to put every instrument from all cultures into a specific category.

The first of the 4 levels is known as the Idiophones, which includes all the instruments that produce sound through the actual body of the instrument as oppose to the vibration of a string or column of air. Sub-categories include struck idiophones, plucked idiophones, friction idiophones, and blown idiophones.

Next, the Membranophones consists of any instrument that produces sound by the vibration of a tightly stretched membrane, such as a drum.

Third, instruments that produce sound through the vibration of a string or strings are categorized as Chordophones. Sometimes, these are referred to as "string instruments"

The last of the 4 main categories is Aerophones, in which sounds is produced by vibrating air. There are no strings and the body itself doesn't vibrate.