Cream cheese synthesizer

I made an Arduino based synthesizer, following the instructions you can find via this link and added a volume knob and two LEDs to the circuit. It was meant to be a present for my girlfriends brother, but I had no enclosure to put it in, so I used an empty cream cheese container as a makeshift solution. When I gave it to him I promised to make a proper enclosure later, but he loves his cream cheese synthesizer, so it will stay as it is. I soldered an iphone charger cable to it that I found in the trash so it can be powered by any USB port. However without adding LEDs a powerbank would turn off because the synthesizer consumes so little energy. I used this workaround before when I created KRAVOX.