Polyphonic Subtractive Synthesizer

The key A on your computer keyboard maps onto the note C, and the letters to the right of A (SDFGHJ) map onto the notes above C in a C major scale (DEFGAB). The letters WETYU map onto the black keys of a piano.

The synthesizer constructs voices according to the amplifier and filter ADSR settings. The amplifier ADSR modulates the gain of the signal over time, and the filter ADSR modulates the detune of the cutoff filter.

• Attack refers to the number of seconds until the maximum level.
• Decay refers to the number of seconds between the attack level and the sustain level.
• Sustain refers to the steady value as the note is pressed as a fraction of the maximum level.
• Release refers to the number of seconds from releasing the note until a zero value.

Credit to Stuart Memo for the keyboard.