About

What is music synthesis?

It is the process of creating new sounds, usually using a computer. New sounds are created
by varying the pitch, volume or timbre of the sound.

Pitch is dependent on the frequency of the sound wave produced during synthesis, but is
also influenced by the mathematical relationship between the frequencies of notes.
Volume is a measure of amplitude of the sound produced.
Timbre is associated with the shape of the waveform of the sound produced. Different
instruments playing the same note at the same volume sound different because they produce
sounds with different timbres.

Voices in synthesis

A voice is a single sound source. For example, a clarinet (a musical instrument) is a
voice in an orchestra. Extending this definition, “voicing” is the actual quality
of the sound – it’s tone, shape (sine/square/pulse etc.) and
colour (like white/pink/brown etc.).
Voicing helps us to explain monophonic synthesis.

What is a synthesizer?

It’s a musical instrument/tool which can be used to generate new sounds or imitate the sounds
of existing instruments. Essentially, it performs the job of music synthesis.

Synthesizers are used for:

1. Creating background sounds, such as the sounds of a spaceship in a movie.
2. Simulating existing instruments, such as a piano, or a guitar.
3. Creating entirely new sounds.

Most synthesizers have three important parts:

1. Controller
2. Performance controls
3. Parameter controls

Controller

This refers to the physical interface used by the musician to create music.
Multiple types of controllers exist, such as pedal controllers, drum controllers, and the most common type–keyboard controllers. Some examples are shown below.

Pedal controller

Drum controller

Keyboard controller

Performance controls

These are usually knobs which are used by the musician to control the pitch of the sound in
real time.

Parameter controls

These are knobs which allow the musician to set the characteristics of sound which would stay
constant during the performance. These controls are used to set the basic properties of the sound.

Air Synth

Air Synth is a monophonic synthesizer which uses Inertial Measurement Unit (IMU) sensors as the controller.
These IMU sensors are attached to a glove and enabled/disabled using a button.
It can play a single note at a time, similar to instruments such as the clarinet
or brass instruments. We have chosen to perform imitative synthesis, i.e. synthesising sounds of existing instruments.

Latency considerations

A typical keyboard player can tolerate latencies between 6ms and 23ms as mentioned by Martin Walker on Sound on Sound.