ooof... I would ask that you either wait until my latest updates have been merged, or that you grab the absolute latest from my PR branch on the repo. the readme is pretty robust with example usage, etc.
through the course of the jam, I learned there are some pretty nasty bugs, and a fundamentally poor approach to managing the lifetimes of the resources which must be owned by the engine. so basically i revamped the whole PGEX to fix that and to make it simpler to add sounds and waveforms into containers without causing memory ownership and lifetime issues.