harmoniums

Harmoniu ms are a type of pump organ that produces sound by air forced through metal reeds. Air is supplied by a bellows operated by the player, either with the feet on a pedal mechanism or by hand on portable models. When a key is pressed, valves are opened to admit air to selected reed banks, and the vibrating reeds produce the pitch. The instrument's timbre is influenced by reed material, tuning, and the number of reed banks or stops.

Historically, modern harmoniums originated in 19th century Europe as portable substitutes for pipe organs. They spread to many regions, including India, where they were adapted as a standard accompaniment for Hindustani and Carnatic vocal and instrumental performances. Indian harmoniums are typically compact, with one or two manuals and often incorporate features such as a built-in drone or multiple reed settings.

There are two main traditions. European style reed organs were common in churches and small concert spaces during the late 19th and early 20th centuries but declined with the rise of electric organs and keyboards. In South Asia the portable harmonium remains widely used for practice and performance, while some Western musicians use period or documentary models for historical contexts.

Today harmoniums are most commonly encountered in traditional, devotional, and classical contexts in South Asia, and in historical ensembles elsewhere. They are valued for their portability and distinctive reedy tone, but their pitch stability and action have sometimes drawn criticism.