What is a Theremin and How Does it Work?

Music is a multifaceted, interdisciplinary art form. From the standpoint of the average consumer, the focus usually lies on the emotions it elicits, the topics it addresses, and the communities it facilitates. Meanwhile, producers are often preoccupied with the technical aspects of music and the application of theory to evoke various emotions. They do so in a broader imaginative and creative space, commonly referred to as ‘flow.’

Yet, music goes far beyond art and creativity, as it often intersects with disciplines like physics, computer science, and engineering, allowing for the development of new, innovative tools. Among them are electronic music instruments, including analog and digital synthesizers. Such tools use analog circuits and signals or digital signal processing (DSM) to generate and manipulate sound. Their development and programming require a profound understanding of how sound ‘works’ and what electronic components are necessary to generate audio.

Today, we will examine one of the arguably most fascinating, mesmerizing inventions in electronic music and the perfect example of how science and music intersect: the theremin.

The theremin is an electronic music instrument controlled without any physical contact. It was developed in 1920 by Leon Theremin (Lev Sergeyevich Termen) in the USSR. Considered one of the first electronic instruments, it played a significant role in the history of synthesizers and electronic music technology. Nowadays, musicians can choose from a wide range of theremins, including the Moog Theremini, Burns B3 Deluxe Theremin, or the (now discontinued) Moog Etherwave Pro Theremin. And, with some luck and a good amount of money, they may still get their hands on a rare vintage RCA Theremin from 1929. Let’s look into the technology and science behind the instrument.

The theremin consists of two antennas attached to a ‘box’ with knobs (one for the pitch and one for the volume), oscillators, amplifiers, and a speaker. It uses electricity to produce two circuits, with pitch generated by the oscillators. One of them is fixed, and the other is variable. The circuits are connected to and ‘processed’ by the two antennas surrounded by electromagnetic fields. The vertical antenna is responsible for the pitch, the horizontal one is responsible for the volume.

Both parameters are controlled by a thereminist’s hands, who uses their body to interfere with the electromagnetic field created by the antennas. The instrument then measures the difference between the oscillators and translates it to a pitch. This is possible because the human body itself conducts electricity and stores electric charges. By interacting with the instrument’s electromagnetic field, the oscillations of the Theremin get disrupted: the closer their hand is to the vertical antenna, the higher the pitch. In contrast, closer proximity to the horizontal one decreases the volume. The signals are then amplified and sent to a speaker.

From a technical standpoint, the theremin involves further elements and processes that require a profound understanding of physics, electricity, and electromagnetism, among other things. In all honesty, we do not fully understand them either 😋. For this reason, it would be highly challenging for a layperson to build one at home. Because of its complexity, it is also one of the toughest instruments to play, which is why it did not achieve much commercial success.

Still confused? Don’t worry, we are, too. Thankfully, some artists mastered the instrument, allowing us to get acquainted with the sounds it produces. In the video below, Leon Theremin offers much insight into how exactly his invention works:

The sound of the theremin is often described as similar to that of a violin, cello, or opera singer's voice. Yet, as an electronic instrument, it can produce a wide variety of sounds, usually described as eerie, haunting, and glitchy. Thus, it makes much sense that it has frequently been used in classical music, more specifically orchestral pieces, and films falling into the genres of sci-fi, thriller, and horror.

Although the theremin was, in many ways, too complex to achieve commercial success, its impact, value, and fascinating character are widely recognized in music. Nowadays, its sounds can be found in various VSTs, such as Omnisphere, and continue to be used in digital music production and beatmaking. So, the next time you work on an eerie-sounding beat or instrumental, try incorporating the theremin for some extra spookiness 👻.

Before leaving, check out this version of Pink Floyd’s song “The Great Gig in the Sky” played on the theremin.