I'm trying to better understand the layout below. Which is based on a project called "Kraakdoos"  which is a touch based musical instrument. And sources suggest that it uses "‘malformed’ oscillators that were very unstable and highly sensitive for finger connections".
However from what I can tell of the circuit there are no explicit oscillators. Is this correct? It simply seems to be a high gain opamp (inverting configuration?). So my question is where does the oscillation come from?
Also am I correct in understanding that the transistors at the output are a push-pull output stage?
The circuit is our course in some respects intensionally wacky, but I'd like to understand it a little better.