Hornbostel–Sachs classification

What it means

The Hornbostel–Sachs classification is an internationally widespread classification of musical instruments by the way they produce sound. It was published in 1914 by the musicologists Erich Moritz von Hornbostel and Curt Sachs and starts from the idea that not form or origin but the vibrating material determines the sound.

Musical use

The system distinguishes four main groups: idiophones, in which the sounding body itself vibrates, such as xylophone or triangle; membranophones with a vibrating membrane, such as drums; chordophones with vibrating strings, such as violin or piano; and aerophones with a vibrating air column, such as flute, trumpet, or organ. A fifth group was added later, the electrophones with electrical sound generation. Each main group is further divided into subgroups designated by numeric codes. The scheme suits instruments of all cultures and is used in museums and ethnomusicology.

The Hornbostel–Sachs classification should be distinguished from the division by orchestral families such as strings, woodwinds, and brass, which is oriented to the orchestra and counts, for example, the flute as a woodwind despite its construction. The classification, by contrast, goes solely by the production of sound.

Performance practice

Use the classification to understand instruments by their sound production: with an unknown instrument ask what vibrates and assign it to a group. This lets you recognise kinships, for instance between piano and hammered dulcimer, both chordophones.