What is a synthesizer? How does it work? What can it do? These are good questions for the person wanting to learn more about synthesizers or maybe even buy one for themselves.

Synthesizers have a lot to offer musicians and want-to-be musicians because they come in many sizes and price ranges. When you buy a synthesizer you are, in a sense, buying every instrument in the band. From its keyboard and other accessories, a synthesizer can produce the sound of almost any instrument in the band.

What Is a Synthesizer?

vintage synthesizer

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You ask, “What is a synthesizer?” Well, in its most basic form a synthesizer is an electronic instrument centered on a keyboard that produces a wide variety of sounds. Need a violin? A trombone? An electric guitar? Synthesizers have them all.

To synthesize something means to put existing elements together to create something new. In that sense, the synthesizer is aptly named, because it combines signals from frequencies to create new sounds, from instruments to footsteps, to howling wind.

How Does a Synthesizer Work?

To answer the question, what is a synthesizer, we need to be able to answer the question, what is sound? Synthesizers create and mimic sounds. What does that mean?

modern what is a synthesizer

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Understanding Sound

Sound is a combination of energy waves that travel from something moving or vibrating. Sound waves travel on a plucked guitar string or a vibrating drum head. An energy wave naturally expands and contracts (rarefactions and compressions) the surrounding air, so air is necessary for sound.

What do these energy waves sound like? Well, it all depends on how fast the wave vibrates (frequency) and how much energy the wave carries (amplitude).

Musical Features

If a trombone and a saxophone play the same note (with the same frequency and amplitude), why do they sound different? The answer is because the sound waves are not the same. Many of their features, such as shape, harmonics, and wave envelope, are still very different.

The shape of sound waves vary dramatically from zigzags to triangles to squares. On a tuning fork, the sound wave will curve. The same note on any other instrument will take a shape similar to that instrument.

Now, wrap your mind around not one single sound wave but a combination of many soundwaves at once to produce one musical note. This is the idea of harmonics. Harmonics are measured in frequencies (Hz), and each instrument has unique harmonics.

Each instrument and its unique harmonics varies in volume over time. A musician can change the volume of his playing gradually or abruptly. This changing volume pattern is an instrument's wave envelope, and no two are the same.

So what is a synthesizer, and how do these musical features affect our question? A synthesizer electronically controls sound waves, including shapes, harmonics, and envelopes, to create or mimic sounds.

How Does It Do That?

What is a synthesizer oscillator? Essentially a sound tone generator, it can produce waves of different shapes and combine them to make new sounds. It can also vary shapes, harmonics, and envelopes to mimic the sounds needed by a musician.

It is easy to think of a synthesizer as combining various sound waves to create something new, and this is often true, but synthesizers also use subtractive synthesis.

In other words, often a synthesizer will start with a large collection of sound waves and eliminate all those unnecessary to produce the required sound. Synthesizers can start from scratch and build sounds, or they can start with a very large collection and eliminate sounds.

Types of Synthesizers

To thoroughly answer the question, “What is a synthesizer,” one must address the type of synthesizer you are talking about.

Modular Synthesizers

Earlier synthesizers were made to generate and combine real sound waves. These are known as modular synthesizers and are sometimes referred to as analogs.

Modular synthesizers used a combination of modules that created certain sound waves that were then connected together. These modules led to the name, modular synthesizer.

Digital Synthesizers

Rather than working directly with actual sound saves, digital synthesizers utilize computer chips. The chips can generate and combine sounds. An advantage of digital synthesizers is their ability to work cohesively with a musician's computer through a digital interface.

Other digital synthesizers, through the use of samplers, can input real sounds such as a thunderstorm that is recorded and downloaded, and manipulate it into other music.

How Do You Use a Synthesizer?

If you can answer the questions, what is a synthesizer, you may be itching to ask, “How can I use a synthesizer?” That is a fair question. The first thing you will need is access to a synthesizer.

The variety of synthesizers and their features can be overwhelming. It is wise to find one synthesizer and stick with it until you are a competent synthesizer musician. If you already have a synthesizer, great! If you have access to one, be sure you will be allowed to use it consistently without switching all the time.

If you are determined to invest in a synthesizer, be sure to pick the right one for your needs.

a man toy over the synthesizer

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Choosing a Synthesizer

You should strongly consider purchasing a subtractive synthesizer. You already know a subtractive synthesizer begins with a large collection of sound waves and eliminate those unnecessary to produce the sound you want.

We live in a digital age, and the subtractive synthesizers have endless possibilities with digital technology. Your options will grow as long as your aptitude for the synthesizer grows.

However, it will serve no great purpose to make your first synthesizer a high-end selection of every bell and whistle other than to make you spend more money than you need to and leave you hopelessly overwhelmed.

Sequencer Selection

Sequencers are sometimes built into a synthesizer. They allow it to arrange notes for playback. This can be very useful for your first synthesizer because you don't have to fuss with an external sequencer.

As you move on in your synthesizer journey, especially for digital synthesizers, MIDI sequencers can pull together various sound sequences (even from different synthesizers) and play them back as an ensemble in a single sound module.


You will need to determine if effects are important to you and how many you want built into your first synthesizer. Effects can include reverberation, distortion, and other things to alter the sound in your module.

At a later time, you will always have the option to add an effects pedal to your synthesizer setup. They are surprisingly cheap and come with a lot of sound options.


A multi-timbral synthesizer can play different sounds on digital channels and synthesize them to create a combined sound in one channel. This would be useful with a standalone sequencer (as opposed to a built-in option) that can handle multiple channels.

Finding Familiarity

Once you have access to a synthesizer, you need to familiarize yourself with the device and the sounds it produces. Find your favorite sounds as well as those you think you will need.

Are you a percussionist at heart? Then find the best snare, toms, bass drum, and ride and crash symbols available to store them away.

Are you a brass enthusiast? Identify your trumpets, trombones, and tuba.

Need a whole jazz band? Load up your best brass, woodwinds, and rhythm section. The main thing is to know where they are and how to access them.

Preset Tracks

Speaking of the rhythm section, there is a good chance your synthesizer already has complete tracks pre-programmed and ready for memory status. You can have an entire rhythm section playing a swing tune and all you have to do is start adding some melody overtop.

Be careful. This is a great synthesizer feature, but it can also be a crutch. At some point you have to be able to create tracks from scratch, so be determined to graduate beyond preset tracks.

Other Considerations

Much like buying a car, your practical side tells you to look at fuel efficiency, safety rating, and warranty. Yet somewhere deep inside you want a particular color, body style, and eye-catching wheels.

Similarly, you can begin your synthesizer search with concerns for sound quality and durability, but you also may have ideas about your preferred aesthetics and features you may or may not need.

Sound Quality

Simply stated, some synthesizers sound better than others. If you are buying a new synthesizer, overall sound quality in the 2019 market is solid. The question becomes how good you want your sound to be.


Regardless of where your synthesizer came from, at some point a person made an investment. You should be thinking about protecting your investment by making sure you purchase a durable synthesizer.

Their very nature lends itself toward mobility, and that presents pros and cons. A cheaper synthesizer may wear out on its own, but one expensive model may be more susceptible to drops than another.

Be sure to consider the quality of a synthesizer to avoid breakdowns and accidents.


Every synthesizer has its own style, and like a sporty car, that can be an important factor in selecting a synthesizer. Particularly for the person who is investing his own money in a synthesizer, be sure you like what you are getting. Aesthetics matter.

What color do you prefer? What body design do you find attractive? What are you most comfortable playing?

Do you prefer the feel of a broad, narrow synthesizer? Or a traditional piano/keyboard feel? It's your investment and it will be your synthesizer.


What sort of sounds does your synthesizer produce? Do you have what you need for the disco sounds you grew up on? Or are you an urban musician? Or country? Your ultimate goals related to your synthesizer require the necessary features when you make your purchase.

What about extra features? Do you love touchscreens? Or would the thought of it drive you crazy?

And what about arpeggio? How many musicians even know what it means?


Over a half century ago, an electrician wanted to create sound from scratch. He thought it could be done through electric signals. He went on to create a device that disaggregated the properties of sound and electronically manipulate them.

Furthermore, he knew that sounds were the result of vibrations that affected the surrounding air. So the same sound waves caused by a vibrating drum head could be electrically generated. The repeated oscillations create waves that have distinct shapes and other features.

The very early synthesizers emulated traditional sounds, but in hindsight, they were not very realistic. Also, the waveforms of real musical instruments were much too complicated to be duplicated by early electrical machines. But it was a start.

The original synthesizers were modular because every sound was a distinct module that would have to patched together with other modules. It was cumbersome work.

But like everything with technology, it grew better and smaller. By the 1970s all-in-one synthesizers had no obnoxious patch cords. Instead, they were replaced by internal wiring.

The Digital Age

A key point in the evolution of synthesizers came in the late 70s when synthesizers went digital. You could now program synthesizers by stacking sounds in any combination imaginable to create a wider variety of sounds.

Sounds also became more realistic in digital synthesizers, and a person with no musical skill at all could hit three buttons and have a professional sounding trio. They became increasingly popular in the 80s and strongly influenced a generation of popular music.

Everything Old Is New Again

Fifteen years later, analog synthesizers made a comeback and still stands on an even foot with digital synthesizers today. They are not as precise and consistent as digitals, but much like folks who want to hear their jazz music on a vinyl album, there is an endearing quality to analog synthesizers.

What is a synthesizer? Hopefully you can answer that question on several levels. What it means for you as you begin your synthesizer journey depends on your personal preferences and goals. We hope you now have enough information to effectively begin your journey.

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