Synthesizer: Definition, History & Music

Instructor: Greg Simon

Greg is a composer and jazz trumpeter. He has a doctorate from the University of Michigan and has taught college and high school music.

Strap on your nerd hat - we're going to check out the history and performance of the synthesizer. It's weird, it caused a lot of discomfort in the classical music realm, and it's completely electronic!

What Is a Synthesizer?

I hope I didn't offend you too much, but don't worry, I'm the king of the nerds: I make synthesizers as a hobby (who's the nerd!). A synthesizer is a musical instrument that uses electronics to create musical sounds. To understand how it works, we need a little bit of background in acoustics.

First, this is what a sound wave looks like (a sound wave is the pattern of energy that sound makes):

Sound Waves
Sound waves

Notice the nice, natural wave to it? There are regular peaks and valleys, called oscillation (periodic vibration of an object); the distance between each peak is called the frequency. This is made by a naturally occurring sound, such as a flute. Now let's look at a type of digital electronic sound wave:

Square Wave
Square Wave

This is a square wave. It is the first, easiest type of digital electronic sound wave to create. Why is it a square and not a nice pretty wave? The difference is as simple as the difference between two clocks: analog and digital. The sound wave is an analog clock, the square wave a digital clock. Electronics instruments cannot recreate a natural sound wave perfectly. We've come incredibly close at this point, but it's not perfect. Why?

Digital clocks work by having a mathematical tick for each second. They do not have the analog wound spring that is completely smooth in movement. An analog sound is the same way: it creates a natural sound wave. A digital sound (a synthesized sound) attempts to recreate this sound with incremental ticks. You can come very close to a perfect sound wave, if you add enough increments, but it will never be exact.

We've talked at length about the digital type, so there must be an analog equivalent then, right? There is, and it does actually create the pure sound wave that an acoustic type instrument would. It does so by using magnetics to create oscillation. If you were to oscillate a piece of metal through electromagnetic manipulation, you would end up with the earliest type of electric musical instrument: the musical telegraph. The difference in sound creation is that an analog synthesizer will in effect physically modify the electrical current, while a digital synthesizer can only modify the mathematics of the electrical signal.

Radio Roots

Bypassing the musical telegraph, as it was essentially an electrically driven buzzer, the first electric synthesizer was the Teleharmonium - in 1897! It was an electronic version of the organ, and it was huge. While unsuccessful, the concepts it introduced were later improved by Robert Moog and others.

Now that we know the earliest instrument, let's look at perhaps the single most important development in synthesized and electronic music: radio. It wasn't broadcasting music over the radio that was the most important development, but the electronic process of creating a sound through modulation (in this case, manipulation of a sound wave). Radio made it possible to create a sound wave through circuitry and then manipulate its pitch, timbre, and volume through modification of the circuit.

Forms of Synthesis

The advent of modulation led to a boom in something called additive synthesis. Additive synthesis is exactly what it sounds like: layering sound waves from multiple sources on to each other. Functionally, this is created by taking the output signal from one oscillator and passing it through the input of the next oscillator.

Additive Synthesis
Additive Synthesis

Later, sound scientists would develop subtractive synthesis, which basically gave us the backbone for all that we can do today. Where additive synthesis meant to stack multiple sound waves up to create sounds, subtractive synthesis is the inverse: removing parts of the sound wave through manipulating either the source or output signal.

Early Synthesizers

So what instruments did we get during this early period? One is the theremin (1920), an instrument that broadcasts radio waves into the air. You play a theremin by placing your hand/arm between the metal antennas to create resistance (slowing down of the electrical current); this changes the oscillation rate of the radio waves, which changes the pitch and volume of the intstrument.

The Ondes Martenot (1928) also came out of this time, and is still in use today (see Daft Punk, Radiohead, and Supertramp). A keyboard controls the notes, but there's also a thin wire which the performer can touch with a metal ring to change pitch smoothly, like a theremin. The free hand controls dynamics and timbre with switches, buttons, and knobs.

Ondes Martenot, by wonker
Ondes Martenot

Monophony, Moog, and Modular Synthesis: The Three M's

Early synthesizers were only monophonic, meaning they could only play a single note at a time. It wasn't until 1937 that the first polyphonic synthesizer was created - the Warbo Format Organ. The first truly successful and widely marketed polyphonic synthesizer was the Hammond Novachord.

Robert Moog
Robert Moog

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