Why is my "mood cue" not working?
The classic way of wiring up motors, including servos, is to provide them with separate power. The image below should clarify this:



The batteries (in this case) have the sole function of providing power to the servo motor. The "data" pin however goes to the Arduino.

The Arduino itself is powered by the USB cable in this example.

The important point is the blue wire - the shared ground wire. Both the Arduino and the servo (and batteries) must have a common ground.