The Pitch effect changes the sound's pitch up or down. It uses a very high quality algorithm that has virtually no alias distortion or noise (the same as Resample).
Pitch - The percentage to change the pitch.
Quality - Good, better, best or ultra. All of them are virtually alias distortion and noise free. They mainly differ by the steepness of the filter's slope. For example, "Ultra" has the steepest slope, but it is the slowest.