On Synthesizers: What Is A Synthesizer?

Synth pioneer Bob Moog's original column for Keyboard explored issues affecting musicians and technology developers

What is a synthesizer? Is it an electronic marvel that flawlessly imitates all instruments of the orchestra? Or is it the ultimate sonic trip, capable of blowing listeners’ minds at the flick of a switch? Worse yet, is it the creation of a team of demented scientists—a super-computer that replaces musicians and violates the music that we humans know and love?

As of our very first issue, we were lucky to have Bob Moog—who was already an icon in 1975— demystifying this new and exotic instrument called the synthesizer. Above is his column as it appeared in our first issue. Below, it’s uncut and unedited. Of course, the answer is “None of the above.” Synthesizers are a class of new electronic musical instruments. Like all valid musical instruments, they are made of carefully chosen materials which are assembled and adjusted by skilled people. True synthesizers are designed not to imitate existing instruments, but to utilize contemporary technology to extend the tonal resources available to musicians. In other words, synthesizers are a class of new tools for musicians, versatile enough to be used in the production of any kind of music. Synthesizer recordings of music from Monteverdi to Mahavishnu are selling well; composer-performers from Carlos to Corea are expressing their musical ideas with synthesizers. But all synthesizer music is made by musicians. Synthesizers can make sound patterns; only human beings make music!

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This is the first of a series of columns in which we will discuss the basic capabilities of synthesizers and what they mean to musicians. We intend to help you understand synthesizers, select an instrument that is suited to your musical requirements, and develop facility and technique in the electronic music medium. We will describe the features of various types of synthesizers that are currently available. However, we will not actually rate competing brands.

Well then, what is a synthesizer?

A synthesizer is an electronic musical instrument that offers the musician direct control over the basic properties of musical sounds, and thus allows the musician to build up his sound material out of its component parts. This is what “synthesize” really means: To assemble a complete entity out of its component parts. Most synthesizer designers take a simple, direct approach. They design a group of circuits that perform single specific functions in producing musical tones. Then they make it convenient for musicians to adjust and interconnect these circuits. This means that the musician assembles his own “instrument” (tone color) with the resources provided by the synthesizer. The ability to set up rich, musically appropriate tone colors is an important part of synthesizer playing technique. Proficient synthesists often change tone colors many times within a single piece of music.

Some Definitions

In any acoustic instrument, the sound travels from the vibrating element through parts of the instrument that shape, refine, and strengthen it, and then finally out into the open air. Other parts of the instrument are not in the sound path, but provide the means by which the musician controls the sound. For instance, the sound path of an acoustic guitar consists of the strings which vibrate, the bridge which transmits the vibrations, and the hollow body which couples the vibrations to the air. The fingerboard is not in the sound path, but is the “interface” between the musician’s hand and the strings.

We can think of a synthesizer in the same way we think of an acoustic instrument, except that the sound exists in a synthesizer as electrical signals (audio) and becomes acoustic vibrations only when it is fed to a speaker. Any synthesizer worthy of the name will have at least one audio generator which produces the raw audio tone, one filter which tailors the sound by emphasizing some overtones and cutting down others, one amplifier that shapes the strength of the sound, and one controller (such as a keyboard or fingerboard) that translates the musician’s “commands” into sound changes. Each of these circuits is called a module or section of the synthesizer. The musician adjusts each of them by means of the panel controls, and interconnects them with patch cords (audio cables), panel switches, or matrix pins. Large synthesizers enable the musician to produce complex sonic textures, or to play more than one tone at a time. However, we shall always be able to talk about synthesizers in terms of their audio paths and the controllers that electrically adjust the audio paths’ modules.

In November/December: The Keyboard – The Musician’s Handle On The Electrons.