Set vibrato waveform
Where [E][4][x] means "set the waveform of succeeding 'vibrato' effects to wave #x". [4] is the 'vibrato' effect.  Possible values for x are: 0 - sine (default) 4  (without retrigger) 1 - ramp down 5  (without retrigger) 2 - square 6  (without retrigger) 3 - random: a random choice of one of the above. 7  (without retrigger). If the waveform is selected "without retrigger", then it will not be retriggered from the beginning at the start of each new note.