The pump organ before 1700 was completely unknown in Europe; it was introduced by the Chinese in Russia in the second half of the 18th century and quickly spread to the rest of Europe, thanks to C. Kratzenstein, a Danish philologist who created the first known model.

Over time, the structure of the instrument underwent modifications, evolving into a proper organ equipped with an air reservoir, a keyboard, and two pedals to operate the bellows.

Between the late 19th and early 20th centuries, the pump organ gained popularity, particularly in small churches and homes. However, larger churches preferred pipe organs due to their greater sound volume and versatility. Despite its sonic limitations, the pump organ became a staple in small churches thanks to its lower cost and smaller size, which made it easily transportable to remote regions. During the era of imperialism, the pump organ was often the instrument of choice for long journeys due to its compact dimensions, allowing it to be carried to regions lacking roads or railways.

The pump organ was also widely used in the United States, where construction techniques were refined in the late 19th and early 20th centuries. Various models were developed, differing in size and sound quality. Some were as small as a chest of drawers, while others produced sounds unaffected by environmental conditions like humidity or heat. These attributes contributed to its popularity in hot climates across southern Europe and the Americas. By the 20th century, the pump organ reached the peak of its popularity, with many models being built—some basic in design and functionality, others elaborate and costly with intricate cabinetry.

It is important to note the existence of two main types of pump organs: the French-style harmonium, an organ using compressed air, and the American-style suction air organ, or reed organ. Both types were eventually replaced by electric organs in the 20th century. Below, we will examine the structural features and various types of pump organs developed over the years.

How is a pump organ made?

The pump organ, also known as the reed organ, shares similarities with aerophones like the bagpipe, gaita, or zampogna, as it includes an air reservoir.

It is equipped with a keyboard and two pedals that operate the bellows to produce sound by driving air through the reeds.

Various types of pump organs differ primarily in their mechanism for filling and operating the reeds. Let’s explore the main models in detail.

The French Harmonium

The compressed air organ, or harmonium, became popular in France in the first half of the 19th century and quickly spread across Western Europe.

Its construction includes bellows or air bags inflated via a reservoir, causing the reeds to vibrate.

Thanks to inventor and organist Auguste Victor Mustel, the harmonium underwent significant structural improvements, enhancing both its sound and design. Mustel’s models were highly regarded for their craftsmanship, often employing premium woods like rosewood and oak, which positively influenced the instrument’s tone and durability. These qualities made the compressed air organ a staple in liturgical celebrations and informal settings, showcasing its versatile applications.

The tone variations stemmed from the design of the reeds, whose shape determined the instrument’s unique timbres. Additionally, players could adjust dynamics using free-reed registers and knee-operated levers.

The American Reed Organ

The suction air organ, or reed organ, emerged in 19th-century America.

Crafted by skilled artisans, early models varied widely. In the reed organ, bellows draw in external air, causing the reeds to vibrate. Like the French model, the American pump organ features pedals and a keyboard. However, designs varied greatly over time; early 20th-century models often showcased intricate and personalized craftsmanship, while mass-produced models became more standardized in form and materials by the mid-century.

In the 1950s, foldable organs were introduced, allowing easier transportation. The type of wood used significantly influenced sound quality, offering distinct tonal variations depending on the material.

This instrument was prized for its versatility, as demonstrated by various recorded performances.

The Indian Harmonium

This eastern variation closely resembles Western pump organs but is designed with compact dimensions for portability.

The instrument features a rectangular design, played with one hand operating the keyboard and the other managing the bellows, located on the side.

It includes a system that produces a continuous background drone, enriching the musical performance.

How is it played?

The pump organ operates intuitively: pressing a key activates a reed, allowing air from the bellows to pass through and produce sound.

A variety of sounds, called stops, can be activated using knobs to enhance the instrument’s versatility.