i only know whats a d s r..
a - attack (time taken for the note played to reach its peak)
d - decay (time taken after the peak for the note to go down)
s - im not sure. might be sustain
r - release depth (the note wil ring softly after the decay has gone down)

its like a mountain graph..


a d r
_
/ \
/ `~

i never really played jazz before..... T_T
can u teach me some chord improvisations?
would love to try if i had the chance........