Specifies the curvature of decay stage of the envelope.
0 is linear, positive values are slower curves (that means the envelope will initially not decay out much, and most of the decay will happen towards the end of the decay period) and negative values faster (quick initial decay with quiet tail decaying more slowly). Past 10 or -10, there’s little difference - at that point, the envelope is practically a horizontal line and a vertical line (if positive) or a vertical line followed by a horizontal line (if negative). Default is 0.
As aid to estimate what the values will do, here some examples.
All curves were made at 120bpm with
note held for 2 seconds. Each vertical line represents 0.5 seconds.