Hello, I am fairly new to electronics besides having to solder an electric guitar's pickup wires. I recently have been trying to research some fun electronics projects I could possibly do and the most simple and cheap was an oscillator circuit I found here, which I modified, replacing a resistor with a potentiometer to control pitch (that version here). I bought all the parts I figured I would require and took a few hours to solder all of the pieces together according to the circuit. I plugged a guitar cable into the audio jack wired to the RC4558's 2nd OP amp's Output for the Tip and I grounded the Sleeve to test it. No sound would come out though. I checked all connections and it seems they're soldered tight, and I even did many continuity tests and voltage checks with my multimeter. I have no clue what I could have done wrong, as I am a beginner into electronics with little experience on building cool stuff. I made a video showing my build and how it's wired to the best extent I could, any questions on it I will answer. I appreciate any help that could be given, and I apologize if I had left out any important information.