The most common type of envelope generator, producing a four-segment signal corresponding to four phases of a note’s dynamics (in the usual case where the signal is used to control a voltage controlled amplifier that determines the note’s volume).Each letter of the acronym stands for one of the four phases, in time order: attack, decay, sustain, and release. A typical ADSR allows the performer to set rise/fall rates for attack, decay, and release, and a level for the sustain phase.(Fancier envelope generators may have more settings or more operational phases.) Conventionally, an ADSR is triggered by the leading edge of a gate signal. The gate going high initiates the attack phase, in which the ADSR’s output rises from the zero level to a set maximum level at the chosen rate.This is immedia