Even though many synthesizers possess the ebony and ivory keyboard of a piano, the rest of the machine — a chassis lined with knobs, dials and switches — looks more like it belongs in a garage instead of a concert hall. Nonetheless, the synthesizer contains the same two components as almost any other instrument: a generator and a resonator. Think of a violin, for example: the strings and the bow are the generator, and the body of the violin is the resonator. On a synthesizer, the generator is the osillator, and the resonator is the filter.
For starters, let’s look at the basic parts of a classic analog synthesizer. (We’ll talk about digital synthesizers later.) Analog synthesizers generate their sounds by manipulating electric voltages. The oscillator shapes the voltage to produce a steady pitch at a given frequency, which determines the basic waveform that will be processed elsewhere in the synthesizer. The oscillator can be controlled by the keys similar to a piano keyboard, a revolving pitch wheel or another tool on the synthesizer’s interface. The oscillator feeds the signal to the filter, and the musician turns knobs and dials to set parameters around the frequencies of a sound — for instance, eliminating and emphasizing specific frequencies like we talked about earlier. The sound passes from the filter to the amplifier, which controls the volume of the sound. The amplifier generally includes a series of envelope controls, which help determine the nuances in volume level over the lifespan of a note.
In an analog synthesizer, each of these pitch, tone color and loudness functions is organized into a module, or a unit intended for a specialized purpose. The earliest modules were encased in their own individual housings. Each module creates a particular signal, or processes it in a particular way, and by connecting these modules together, the musician can layer, process and change the sounds into something different.
Now that we know about how synthesizers work, let’s look back at their history.
Early History of Synthesizers
When was the first synthesizer invented? That depends on who you ask.
Many point to the Telharmonium or the theremin — instruments invented in the late 1890s and in 1919, respectively — but Rhea disputes their inclusion: Nothing on these instruments grants the operator complete control over the constituent elements of sound. The first instrument to fit the criteria was a hybrid of piano and electronic technologies invented in France in 1929 by Armand Givelet and Eduard Coupleaux, which used a paper tape reader and devices that manipulated elements of electronic circuitry in order to create an orchestra of four voices. The first time the word “synthesizer” was used to describe an instrument came with the 1956 release of the RCA Electronic Music Synthesizer Mark I, which used tuning forks and information punched onto a roll of paper tape to play music through a set of loudspeakers
Robert Moog is generally considered the father of the modern synthesizer. Moog, an American, was an electrical engineer who dabbled in building electronic instruments like theremins. In the early 1960s, after befriending the musician Herbert Deutsch, Moog set about inventing the first commercially available synthesizer. Released in 1964, Moog’s 900 Series Modular Systems resembled towering mainframe computers with a spiderweb of cables that “patched” the various modules together to create a complete sound. The sounds could be sequenced as well as played in real time.
Initially marketed toward academics and experimental musicians, these synthesizers were polarizing instruments early on. “As a salesperson, I went into music stores where I was practically thrown out, and I was told that [the synthesizer] wouldn’t be a musical instrument,” says Rhea, who spent many years working alongside Moog in many different capacities. But in 1968, the Grammy-winning album “Switched-On Bach” by Wendy Carlos exposed the musical possibilities of synthesizers to a broader audience. In subsequent years, groups like Parliament-Funkadelic, the Mahavishnu Orchestra and Emerson, Lake, and Palmer began incorporating synthesizers into their music. The advent of the Minimoog, which consolidated elements of the large devices into a single, portable instrument that was less expensive, put 13,000 synthesizers into the hands of performing musicians during its production life. Even after the advent of digital synthesizers, musicians continue to honor Moog and his creations at the annual Moogfest in Asheville, N.C..