______                     
                 /      |       ________     
                /       |____  /        \    
               /        |    \/   _      \   
               \       ___       /_\      \  
                \      \_/          .      \ 
                 \          /\_____/       / 
                  \________/      |       /  
                                  |______/   

[THE_EXPR_METHOD] 001 modulation and sequencing

Modulation and sequencing are two building blocks that are fundamental to sound synthesis and music making. The former typically aims to control the finer details and the timbre of a sound, whereas the latter deals with the arrangement and the structure of “musical” events over time. Their definitions can briefly be summarized as the following:

Modulation, applying a continuous signal onto a parameter, so the value of the parameter changes smoothly over time.

Sequencing, applying a sequence of values onto a parameter, so the value of the parameter changes discretely over time.

Modulation is generally easier to understand, as it often is taught as the “introduction” to sound synthesis. The three properties of any given oscillating sound (frequency, amplitude and phase) can all be modulated to create interesting results.

Sequencing, on the other hand, is less common to achieve using digital audio signal exclusively. The objective is essentially to quantize the signal into discrete “steps”. As a result, even though the signal is continuous, the changes in its values are quantized accordingly. One can also think of it as the reduction in “resolution” of a given signal. One example would be to make a DSP version of a step counter.

The “trick” to make such a counter is simply to multiply the signal with a (max count) variable, and then only to take the integer part of the result. For example:

[phasor~ 1]->[*~ 5]->[expr~ floor($v1, 0)]

This will result to a signal that counts from 0 to 4 in one second.

Having a good practical understanding on both modulation and sequencing is crucial in grasping and taking full advantage of the topics to come. The following questions can be used as starting points to approach the subject.

What are the differences and commonalities between modulation and sequencing?

Are they essentially the same?

Where can they be applied?

EXAMPLE PATCH: 001_mod-seq.pd

Get the source here