Sorry, my mistake for not showing a polarized electrolytic capacitor in the schematic.I see. I have some of those barrel caps laying around, but I know that they have a positive and negative leg, which is usually indicated on a circuit schematic. Your schematic did not show that, and me being a circuit/engineer dummy, did not know if you can put a cap with pos/neg legs into this type of circuit.
If that all makes sense. I hope that all came out alright.
Yes, +ve leg goes on +9V, -ve leg goes on GND.