From The Editor | November 30, 2023

From Theremins To Synths: The Oscillator's Musical Odyssey

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By John Oncea, Editor


From the invention of the Theremin in the 1920s to the Moog synthesizer's voltage-controlled oscillators in the 1960s to today's digital synthesizers and software, oscillators have shaped diverse musical genres, enabling musicians to create and manipulate an expansive array of sounds.

An oscillator, characterized as a circuit, generates waveform without any mechanical input by creating an alternating current that sends a signal back and forth in intervals. Oscillators are omnipresent, part of many commonly used devices and household appliances. The next you tune into your favorite radio station or television show or even check the time on your watch, consider the oscillator.

Oscillators also have made their mark in the music industry, playing a surprising role in shaping and transforming sound. But before we look at how instruments that evolved from oscillators were used by Led Zeppelin, Taylor Swift, and Sheldon Cooper (playing the Star Trek theme!), let’s take a quick look at the history of the oscillator itself.

Oscillators 101 (This Will Be On The Final)

Oscillators are used in a wide range of disciplines, from physics to engineering, and have roots dating back centuries. One of the earliest forms of oscillators can be traced back to the invention of the pendulum clock by Dutch scientist Christiaan Huygens in 1665, according to The Royal Society.

“Huygens observed that two identical pendulum clocks, weakly coupled through a heavy beam, soon syncronized with the same period and amplitude but with the two pendula swinging in opposite directions,” writes The Royal Society. “This behavior is now called anti-phase syncronization.”

Jump ahead 220 years when German physicist Heinrich Hertz is credited with building the first experimental spark gap transmitters during his historic experiments to demonstrate the existence of electromagnetic waves. Hertz’s first oscillator was a pair of one-meter copper wires with a 7.5 mm spark gap between them, ending in 30 cm zinc spheres. When 20,000-volt pulses from an induction coil were applied, it produced waves at a frequency of roughly 50 MHz.

Around the same time, Nikola Tesla and others were experimenting with inductance-capacitance (LC) circuits to generate high-frequency electrical oscillations. This led to the development of radio transmission technologies.

With the advent of vacuum tubes, particularly the triode, in the early 20th century, engineers and scientists could generate and control oscillations more effectively. Vacuum tubes were used in various oscillator designs, including the Hartley oscillator and the Colpitts oscillator. In the 1920s, researchers discovered the piezoelectric effect in crystals. This led to the creation of crystal oscillators, which relied on the natural oscillation frequency of quartz crystals to generate precise frequencies.

The invention of transistors in the mid-20th century revolutionized electronics. Transistors replaced vacuum tubes in many oscillator circuits, leading to more compact and efficient designs. With advancements in semiconductor technology, the integration of oscillators into small silicon chips became commonplace. This facilitated the proliferation of oscillators in various electronic devices.

Today, oscillators are crucial components in digital systems. Clock oscillators generate clock signals essential for syncronizing digital circuits in computers, microcontrollers, and various electronic devices. There are also various types of oscillators, such as voltage-controlled oscillators (VCOs), phase-locked loops (PLLs), and relaxation oscillators, that serve specialized purposes in electronics, telecommunications, and other fields.

Over time, oscillators have evolved significantly, from mechanical pendulums to sophisticated electronic circuits, playing an integral role in modern technology and serving as the backbone for numerous electronic applications.

Let There Be Rock

Oscillators were initially developed in the late 19th and early 20th centuries for scientific and telecommunications purposes. Like all good things, other uses were found for the technology by other industries, including music.

In the 1920s and 1930s, inventors and pioneers like Lev Sergeyevich Termen (Leon Theremin) developed electronic musical instruments utilizing oscillators. Theremin’s invention, the Theremin, was one of the first electronic instruments that produced sound through hand movements in an electromagnetic field, based on oscillator technology.

According to the BBC, Theremin was 23 years old when he accidentally “invented a machine that aimed to use the new-fangled technology of radio waves to measure some properties of gas. But he found his apparatus emitted a strange warbling tone, which he could shape by moving his hands around the equipment. A trained cellist, Theremin recognized the potential of his discovery and intended to create an entirely new instrument.”

In an interview with Olivia Mattis in 1989, Theremin said, “I was not satisfied with the mechanical instruments in existence, of which there were many. They were all built using elementary principles and were not physically well done. I was interested in making a different kind of instrument … Therefore, I transformed electronic [equipment] into a musical instrument that would provide greater resources.”

The theremin is the only musical instrument that can be played without touching it. The thereminist stands in front of the instrument and moves their hands in the proximity of two metal antennas. These antennas create an electromagnetic field that the musician uses to control the pitch and volume of the music.

The theremin has been used in movies and television shows and is featured in the soundtracks for Spellbound, The Lost Weekend, The Day the Earth Stood Still, and First Man. It also has been used in the theme songs for Midsomer Murders and Loki. A basic theremin can cost around $120, while more professional options can cost between $250 and $500.

Goodbye Grey Sky Hello Blue

The emergence of electronic music in the mid-20th century saw a significant role for the audio test oscillator, according to Reverb. “In electronic music, the tape recorder was adapted from its primary purpose (recording sound) to a new one (manipulating sound). The test oscillator was reimagined similarly.”

Test oscillators are commonly used to generate a sine wave, which can be tuned using a rotary dial. They are primarily designed for measuring the response of electrical circuits and are often used in conjunction with oscilloscopes, which can help analyze the output wave.

However, sonic explorers quickly realized the musical potential of the test oscillator, which offered an infinitely variable tone. As a result, it became a preferred sound source that could be manually “played” using the dial and processed through tape editing and filters. After the end of World War II, there was an abundance of military-surplus oscillators available for purchase, making them an affordable option for musicians and sound engineers alike.

Two electronic music pioneers were Tristram Cary and Daphne Oram. “In 1943, Oram started working at the BBC as a junior studio engineer and music balancer,” Reverb writes. “That same year, Cary joined the Navy as a radar operator.

“Both jobs involved using test oscillators. Cary left the Navy in 1946 and began building ‘the Machine,’ a ragbag of gadgets mounted on an old table and intended to make electronic music. In time, it would incorporate a disc-cutting lathe, which he bought with his demobilization pay, and a collection of military surplus oscillators.”

A decade later, Karlheinz Stockhausen, while working at the Studio for Electronic Music of the West German Radio, advocated using oscillator sine waves as compositional building blocks, demonstrating his approach with Studie I and Studie II in 1953 and 1954.

Cary, Oram, and others continued to find innovative ways to use tape recorders, oscillators, and filters to incrementally advance the popularity of electronic music into the late 1950s. This is when Paul Tanner, a session trombonist who’d played for Frank Sinatra, “witnessed a Thereminist struggling to pitch his instrument to the orchestra,” writes Reverb. “This prompted Tanner to fashion a homemade instrument he called the electro-theremin. It was simply a test oscillator in a box with a manual slider, with notes marked on the box as a guide.”

Tanner utilized his gadget for creating TV themes and recording various sessions before receiving a call from Brian Wilson, which turned out to be a significant moment in his career. As a result of this call, Tanner was involved in the production of several Beach Boys songs, including 1966’s iconic “Good Vibrations” track released in 1966.

Interestingly, around the same time “Good Vibrations” was released, The Rolling Stones were working on their album “Between The Buttons.” The U.K. edition of the album featured Brian Jones playing with a test oscillator over a Bo Diddley rhythm on the song “Please Go Home.” A year later, Brian Wilson used the same technique on the Satanic Majesties album and the commercialization of synthesizers was getting started.

Moving The Needle: Moog And Buchla

The use of oscillators and other related technologies and devices in the music industry was happening in fits and starts until Robert Moog and Don Buchla introduced their groundbreaking designs and “basic synthesizer components such as oscillators, filters, amplifiers, envelope generators, and ring modulators were commercially sold and assembled piecemeal into sound synthesizing systems — primarily for use in acoustic research centers and academic music studios,” according to B&H Foto & Electronics Corp.

The beauty of modular synthesizer systems lies in their complete flexibility. A composer, or rather an engineer in the guise of a composer, would select the components and patch cables manually to create a signal flow that would produce the desired sound timbre.

These systems included not only audio signal modules but also control and logic functions, with many modules overlapping between all three. This allowed for limitless possibilities in signal routings. For instance, random voltages from a noise generator could be captured by a sample and hold circuit and sent to control the clock rate of a step sequencer. One could also patch an LFO (low-frequency oscillator) to modulate the cutoff frequency of a VCF (voltage-controlled filter), which created opportunities for all kinds of Sci-Fi-inspired experimentation.

A 20-Year Lull

Synthesizer technology continued to evolve through the 1960s and 1970s with companies like ARP Instruments and Roland introducing new models featuring multiple oscillators, filters, and modulation capabilities. Disco, funk, and progressive rock prominently used synthesizers with oscillators, expanding their presence in mainstream music.

“Mood synthesizers became particularly popular among progressive rock bands, including Pink Floyd, Genesis, Yes, and Emerson, Lake & Palmer,” iMusician writes. “A whole new sub-genre of progressive rock, krautrock (also known as kosmische Musik) was born in West Germany in the late 1960s and early 1970s, represented by prominent artists such as Tangerine Dream, Can, Faust, and, most importantly, Kraftwerk.”

Although modular synthesizers were widely used by musicians in the 1970s, including R&B and jazz luminaries like Stevie Wonder and Herbie Hancock, as well as electronic artists such as Tangerine Dream and Klaus Schulze from the Berlin School, their popularity was largely surpassed by monophonic synths with fixed-signal-path like the Minimoog, Arp Odyssey, and Oberheim SEM.

“While these classic synths offered far less flexibility than most modular systems, they were prized by musicians for their relative ease of use and rich sound,” B&H Foto & Electronics. writes. “And so it went through the ‘70s to early ‘80s: analog synthesizers and the systems for interconnecting them became more simplified, with patch points appearing for basics such as pitch and gate (note length) and, less commonly, FM (frequency modulation), filter envelope, external audio input, and others. When MIDI and digital synthesizers such as the Yamaha DX-7 finally arrived in the 1980s, the writing was already on the wall: analog synthesizers were about as passé as pet rocks, leisure suits, and 8-track tapes.”

The ‘80s: Pinnacle Of Synth Pop Success

The 1980s marked the peak of synthesizer popularity with the emergence of synth-pop bands like Depeche Mode and New Order using digital synthesizers that incorporated oscillators and other components resulting in more versatile sound creation and expanding their use in various music genres.

“However, the 1980s were defined mostly by the development and rising popularity of electronic dance music (EDM) and, gradually, its subgenres, like house, techno, acid house, trance, and many more,” writes iMusician.

This development eventually led musicians, producers, and DJs to experiment with analog equipment that had for years been languishing in bargain bins, adds B&H Foto & Electronics. “These intrepid explorers of sound devised a futuristic musical vocabulary with even the most primitive of tools, manipulating sonic parameters that had previously been overlooked in traditional rock and jazz contexts.”

Analog instruments like the Roland TB-303 and the Korg MS-20 have gained popularity not only because of their aggressive sound but also due to their ability to interface with complementary equipment. The MS-20, for example, has a semi-modular patch panel that enables users to override the synth's internal connections. This trend toward modularity is evident in modern synths, with most monosynths providing at least CV and gate and many, such as the Moog Minimoog Voyager, Arturia MiniBrute and MicroBrute, and Korg MS-20 Mini, offering a range of patchable parameters.

You Say You Want A Revolution

With advancements in digital technology, software synthesizers and digital audio workstations (DAWs) became prevalent, offering virtual oscillators and a wide array of sound manipulation possibilities. Oscillator-based instruments, both hardware and software, continued to evolve, with an increasing focus on digital signal processing, enabling musicians to create diverse and complex sounds.

In modern times, oscillators remain an integral part of music production, with software synthesizers, modular synthesizers, and various electronic instruments continuing to utilize them for sound generation and manipulation. Their historical journey reflects their transformative role in shaping the sonic landscape of music across genres and eras.