Subtractive Synthesis
Subtractive synthesis is one of the oldest and most widely used forms of synthesizing sounds. It is the method employed in every electric piano and synthesizer. Even the latest digital workstations and samplers employ many of the basic principals of subtractive synthesis.
Subtractive synthesis started life in the modular synthesizers, large cabinets housing separate electronic modules, connected via patch leads. With the advancement of technology, the functionality of these modules could be put onto a single circuit board. But functionality remains the same with the same knobs and dials, familiar to very early models.
The three main elements that create and process the sound are Oscillators, Filters and Amplifiers.