I'm trying to better understand the layout below. Which is based on a project called "Kraakdoos" [2] 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.

[![Layout](https://41j.com/blog/wp-content/uploads/2015/08/kara1.png)](https://41j.com/blog/wp-content/uploads/2015/08/kara1.png)

[2] <http://www.eam.se/kraakdoos/>