Synthesizer Facts for Kids

A musical synthesizer is an instrument that uses electricity to create musical sounds. People often call them "synths" for short. They are the main instruments used to make electronic music.

Many synthesizers have a keyboard that looks like a piano keyboard. When you play a piano, small hammers hit strings to make sounds. But when you play a synth keyboard, it makes sounds by turning electrical parts called oscillators on and off.

How Do Synthesizers Make Sound?
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How Do Synthesizers Make Sound?

An oscillator is something that "vibrates" or repeats a pattern over and over. Think of a clock's pendulum swinging back and forth – that's a very slow oscillator! A piano string also oscillates when it's hit.

In a synth, electric oscillators are often made using tiny electronic parts called transistors. These parts turn electricity into electrical patterns, or signals, that repeat. When you press different keys on a synth, you hear different musical notes. This happens because the oscillator's signal repeats at different speeds for each note.

The sound signal can be made stronger and sent straight to a loudspeaker. But a simple signal can sound a bit plain. Synthesizers have many ways to make sounds more interesting and unique.

Shaping the Sound with ADSR

One way to make sounds more interesting is by changing how quickly they get loud and then soft again. This method is called "ADSR." It helps synthesizers sound more like older instruments, such as trumpets or flutes.

Combining Sounds

Synthesizers can also combine signals from several different oscillators. This helps to create a richer, fuller sound. Imagine mixing different colors to get a new shade – it's similar for sounds!

Using Filters to Change Sound

After combining signals, the sound can be sent through one or more filters. Filters are like sound shapers; they can remove certain parts of the signal. For example, filters can make a sound "brighter" or "duller," or change it from "soft" to "harsh."

Low-Frequency Oscillators (LFOs)

Many synthesizers use special oscillators called "LFOs." LFOs are very slow oscillators that don't make audible sound themselves. Instead, they control other parts of the synth. For instance, an LFO might control how loud and soft the sound gets, or it might change the pitch of the sound. An LFO can even control how the filters work, adding movement to the sound.

By using all these methods together, modern synths can sound very much like traditional instruments. For example, "drum synths" are special synthesizers designed just to make drum sounds. Synths can also create many brand-new sounds that have never been heard before!

Software Synthesizers

In the early 2000s, computers became powerful enough to run "software synths." These are computer programs that act just like real synthesizers. They are often less expensive than physical synths, which means more people can use them. Some of these programs can even be downloaded for free.

Playing Synthesizers

There are special tools that help musicians play synths. For example, a "wind controller" lets players of wind instruments use their unique skills to control a synthesizer. People are always looking for new ways to control synths to make them even more expressive and fun to play.