First song, Turn ON the power. Then, On spawn room. There’s a computer, Press three times and the song will start. Computer location is near windows.

Second song, go on tunnel 11 straight at the end door going to power room. On that door there’s a circuit board, press three times and your song will begin.

Third and final song, Its on laboratory. go on the top level and go straight to Bio Dom door. On your right, there’s a computer. Press three times and guess what, your song will start again.

Note: This can be played once in every gameplay.