What is modulation in musical production?
Before becoming examples, let us understand what the modulation of music is. Essentially, it is the change in the properties of sound over time. Instead of keeping parameters such as height, volume or static tone, modulation allows you to handle them dynamically. This movement can be subtle as a slight vibrato on an advance – or extreme, like a groan of chaotic bass.
The modulation makes a living track. Without this, synths may seem rigid and the effects may feel flat. Used properly, modulation adds depth, movement and variation and can make the simple elements more attractive.
Modulation applies to almost all aspects of sound design and mixture. It is used in synthesizers, effects for processing effects and mixing to create a movement in different ways. The most common types of modulation include:
- Synth modulation: using LFOs, envelopes and other modulation sources to dynamically modify the sound of a synth.
- Modulation effects: effects like the choir, the phaser and the steering wheel that add movement to a sound.
- Frequency modulation (FM) and amplitude modulation (AM): synthesis techniques where a wave form modifies the sound of the other. These are relatively similar techniques in theory but differ in the aspects of wave forms used as a source of modulation.
An example of synth modulation can be heard in the classic Skrillex Brostep track “First of the Year (Equinox)”. Listen to the growing synths that start at 01:27. Here, Skrillex modulates various parameters over time such as the position and filtering of the wave to make an aggressive “growl”.
