Pump organ

The Pump organ is a member of the free reeds and interruptive aerophones (Hornbostel–Sachs 412.132). Its invention is credited to Christian Gottlieb Kratzenstein and Alexandre Debain. Learn how it makes its sound and explore related instruments.

How the Pump organ makes its sound

In the Hornbostel–Sachs system, which classifies instruments by how they produce sound, the Pump organ belongs to the free reeds and interruptive aerophones: air is periodically interrupted by a vibrating reed or blade – the accordion, harmonica, sheng and bullroarer.

More broadly it is one of the aerophones (wind instruments), where sound comes from vibrating air.

Players shape its sound through technique and materials; the resonating body filters the raw vibration, boosting some harmonics and damping others.

From Wikipedia

The pump organ or reed organ is a type of organ that uses free reeds to generate sound, with air passing over vibrating thin metal strips mounted in a frame. Types include the pressure-based harmonium, the suction reed organ (which employs a vacuum system), and the Indian harmonium. Historical examples include the Kunstharmonium and the American reed organ, while earlier forms include the physharmonica and the seraphine.

More portable than pipe organs, free-reed organs became widespread in smaller churches and private homes during the 19th century, although their volume and tonal range were limited. They generally featured one, or occasionally two, manuals, while pedal-boards were rare. Higher-end pump organs offered a broader range of tones, and models intended for churches or affluent households were often housed in finely crafted cabinets.