I am reading the book "Electronic Music Circuits" written by Barry Klein and there is a section where he is going over oscillators. He explains that the AD818 is used as an exponential converter. To me, what I see are two npn transistors connected to one another via the emitter. Q2 NPN Transistor has the base connected to ground. I am not sure how that transistor gets powered on when the base has no voltage. Can anyone explain why or how this IC functions in this case?

 

It looks like a translinear circuit, but I'm not sure about the next stage or it's effect on the global feedback with that setup.

...now I know what book to pick up next, very cool question.