Nice idea JD. I was thinking about this a while back when I was after a Jean Michel Jarre "bomb falling" type sound. However I'm not sure how this would work in practice. What would the pitch range be? How would you know what note you were starting and finishing on? After all, in the envelopes, you've only got a line to work with. I'd be interested to hear your thoughts on this, also what did you mean by a "pitch shifting algorithm"?