Glossary

Additive synthesis

A synthesis technique that builds complex waveforms by combining sine waves with variable frequencies and amplitudes.

Amplitude

A song or electrical signal’s level or volume. Amplitude refers to the height of the waveform -- the higher the waveform, the greater its amplitude and the louder the sound.

Analog

Production of soundwaves using voltage controlled circuits. These circuits are typically associated with a “warm” sound.

Arpeggiator

A feature that creates a pattern it then steps through based on an input note or chord. It is based in arpeggios, which are a type of broken chord wherein the notes of a chord are played in ascending or descending order.

Attack

The time it takes for the start of the sound to reach its maximum volume.

BPM

Beats per minute, which is used to determine how fast a song is. Also called tempo.

Compressor

A dynamic effect that boosts the volume of a signal and then reduces (or attenuates) the peaks of that signal at a certain threshold, preventing the sound from peaking or distorting.

Cutoff

The point or frequency at which the filter effect kicks in.

CV or Control Voltage

The voltage levels that are used to control functions and parameters in analog synthesizers.

Cycle

One complete vibration of a sound. The pitch of sound waves is measured in cycles. One complete cycle per second is 1 Hertz (Hz).

Daisychain

To connect a group of devices or modules together in a series.

DAW - Digital Audio Workstation

Computer software such as Ableton Live, FL Studio or Logic, which can be used to record, edit and mix audio.

Decay

The second stage in the ADSR envelope, this is the time it takes for the sound to die away after it has been triggered.

Decibel or dB

A unit used to measure sound level.

Delay

An effect that mimics the time difference between the arrival of a sound and its audible first reflection.

Digital

A digital synthesizer uses digital signal processing to make sounds.

Also see: Analog

Distortion (also known as Overdrive)

An effect based on the sound of sending too much voltage through an amplifier.

Effect (often abbreviated to FX)

A process that modifies the audio, either by modulating it (flanging, phasing, chorus), applying a spatial quality (reverb, echo, delay), dynamic effect (compressor) or overdriving it (distortion). These can be built into synthesizers, exist as standalone modules, come in external pedals or be added in a DAW.

Envelope

A waveform that changes over time.

Envelope Generator

Used to shape the sound through attack, decay, sustain, and release.

Feedback

The routing of some of the output of a device back into its input.

Filter

A process that removes certain frequencies and harmonics and allows others to pass through. A low-pass filter only allows frequencies below its cutoff frequency to pass, resulting in low frequencies or low-pitched sounds coming through.

FM Synthesis

A synthesis technique known as frequency modulation (FM), where the pitch of the oscillator is changed, or modulated, very quickly by another oscillator. This results in a complex set of harmonies that complement the fundamental pitch of the main oscillator.

Frequency

Also referred to as pitch. Frequency is the number of times per second that a soundwave’s cycle repeats. The higher the frequency, the higher the pitch heard.

Fundamental Frequency, or Fundamental

The lowest frequency of a periodic waveform.

Gain

The level, volume or output power of a signal.

Gate

a) A signal that can turn on and off. Trigger it on when holding down a key, off when releasing the key. Can be used to change the stages of an envelope or start and end a sequence.

b) A dynamic effect that cuts off a sound below a certain decibel level.

Harmonic

A kind of partial tone which is a whole multiple of a fundamental frequency.

Headroom

Available dynamic range which provides a buffer to allow for unexpected loud sounds without risk of clipping.

High-pass filter

A high-pass filter only allows frequencies above its cutoff frequency to pass untouched, and reduces the level of lower harmonics below the cutoff. This results in high frequencies or high-pitched sounds coming through.

Interface

Used for audio recording, this device is connected to one or more instruments and a computer to record into the computer’s DAW.

Jack

The hole that you plug your headphones into, or the hole the patch cables go into, for example an ⅛” or ¼” jack.

Keybed

The rail that stops the downward motion of the key. Also used to refer to the entire piano action, including keys.

Keyboard

A set of keys on a piano or synthesizer.

LFO - Low Frequency Oscillator

An LFO generates an incredibly low frequency waveform, below the range of human hearing. This low waveform can be used to shape the rhythm of any of various processes in synthesis.

Looping

A function that restarts a sample as soon as it has finished, creating a continuous loop.

Low-pass filter

A low-pass filter only allows frequencies below its cutoff frequency to pass untouched, and reduces the level of higher harmonics above the cutoff. This results in high frequencies or high-pitched sounds coming through.

MIDI

An acronym for Musical Instrument Digital Interface, a language that lets electronic instruments and computers communicate.

Modular

A synthesizer in which the different components, such as the oscillator, filter, VCA and VCF are separated into discrete modules that require patching by hand to generate sound.

Mono

In recording, refers to when all audio signals are routed through a single audio channel, as opposed to stereophonic or stereo, where there are two independent audio signal channels.

Monophonic

A synthesizer that can only play one note or sound at a time.

Multitimbral

A synthesizer that can play multiple musical lines at once.

Multitrack

A recording technique that allows for the recording of separate audio streams on discrete tracks.

Noise

Random voltage fluctuations without a distinct pitch.

Octave

The distance or interval between musical notes that are eight notes apart. The C an octave above a middle C (C5) has twice the frequency of vibration, while the C an octave below middle C (C3) has half the frequency of vibration.

Oscillator

The main sound generator. Its output varies (oscillates) in voltage in a repeating pattern, which is referred to as its waveform. How fast this waveform repeats is its frequency or pitch.

Overdrive

An audio signal processing used to alter the sound, usually by increasing the gain, creating a fuzzy, noisy tone.

Pad

A synthesizer’s chord or tone that is used to fill out the background of a track.

Pan

The spread of an audio signal across the sound field, from left to right.

Partial

The elements of sound that go into defining the quality of any given sound. Each waveform has a spectrum of partials associated with it.

Patch

In module synthesizers, this refers to how different modules are connected by patch cables to create a sound. In other synthesizers, patch is another term for instrument or voice.

Pitch

See frequency. Refers to how high or low something sounds.

Polyphonic

A synthesizer that can play multiple notes or tones at once.

Pot

A knob that is turned on a synthesizer.

Release

The fourth and final stage of the ADSR envelope.

Reverb

The phenomenon of acoustic ambience created by soundwaves reflecting in a confined space. This is simulated digitally to create a continuous wash of echoing sound.

Ring modulator

A type of amplitude modulation in which one waveform (the modulator) is used to vary the amplitude of a second waveform (the carrier). The modulator signal’s frequency is both added to and subtracted from the carrier’s, resulting in a complex set of harmonics that create metallic, ringing sounds, hence the name.

Sample

A chunk of audio that can be manipulated and shaped.

Sampler

An instrument in which you can upload different samples and trigger them.

Saw wave

The most harmonically rich waveform.

Scientific Pitch Notation

A way to identify octaves using letters and numbers to allow easy reference to a specific pitch. Middle C is C4, the C above Middle C is C5, the C below middle C is C3.

Sine wave

The most basic waveform solely comprised of the fundamental.

Square wave

A waveform that contains harmonics that occur in whole odd-number multiples of the fundamental frequency. The harmonics, combined with the fundamental, give this wave a square shape.

Stereo

In recording, refers to using two independent audio signals.

Subtractive Synthesis

A method of synthesizing by which a player constructs a sound by filtering out frequencies, rather than adding them on.

Sustain

The third stage in the ADSR envelope, which refers to how sound varies with time.

Timbre

Also known as tone color or quality, this is the characteristic of that instrument that makes the sound unique. For example, the same note at the same volume on a piano and guitar will sound different.

Triangle wave

A waveform that contains the same odd harmonics as a square wave, but they taper off as they get further away from the fundamental, resulting in a triangular shape.

TRS

Two quarter inch cables that carry stereo signal. TRS stands for tip, ring and sleeve.

VCA - Voltage Controlled Amplifier

The synthesizer circuit that controls the volume or amplitude of the signal by changing it depending on the level of control voltage sent to it. Typically the last stage of a patch.

VCF - Voltage Controlled Filter

The synthesizer circuit that reduces the strength of select harmonics or overtones to change the sound. Its cutoff frequency can be changed by altering the amount of voltage being sent to its control input.

VCO - Voltage Controlled Oscillator

An oscillator transforms an electric current into a repeated signal of a waveform, to generate the raw sound which is going to be shaped by the synth’s different processes.

Waveform

The pattern of oscillations--up and down variations in voltage--created by the oscillator, such as square, sine, triangle and sawtooth. Different patterns have different timbres.

XLR

A three-pin connector that is frequently used to carry audio signals for microphones and balanced instruments.