The following schematic is for UM66 or BT66 musical IC. You need very few components to make this circuit.
Pin configuration for UM66 is given below:
Zener diode rated 3.3V maintains the required 3.3V for UM66 IC. The output from Vo of UM66 is amplified by BC547 transistor.
Click on the video to see the output
BuildCircuit proudly recommends EasyEDA for circuit and PCB design