All of the tools we will look at in this book are synthesizers of one sort or another, and they all work in a fairly similar manner. As Figure 2.1 shows:
There is a sound source.
The tone of the sound is changed by a filter.
The volume of the sound is controlled by an amplifier.
Figure 2.1. The typical signal flow in a synthesizer. The sound source creates the sound, the tone is shaped in the filter, and the volume is controlled in the amplifier.
As you will see, the sound can be controlled and shaped by modulators at any stage in the signal path.
There are other sound-generating possibilities, ...