I was just playing with the William Tell Overture in PlayWithMe 8. 
This is in a newly downloaded 2.9alpha VM and image with latest 
update 3125.

I changed the "voice" of one of  the instruments to "oboe2", and 
tried to edit it.  I got a messageNotUnderstood walkback.

Poking around a little bit, it seems that oboe2 (and also flute2) 
have two envelopes: a VolumeEnvelope and a RandomEnvelope.  (These 
may be the only sounds with a RandomEnvelope.) The initialization 
code in RandomEnvelope does not seem to be complete, because although 
it does initialize some of the instance variables, it does not 
initialize the instance variable points.  Consequently, when 
EnvelopeEditorMorph attempts iterate over the points in that 
envelope, it sends collect: to nil.

I don't know what a RandomEnvelope is really for (I'm musically 
impaired) so I can't offer much help as to what the correct value for 
points should be, but it doesn't seem to be nil!

	Andrew