Pitch Variation refers to the differences in the frequency of sound waves, which affects how high or low a sound is perceived. In music, pitch variation can be created by changing the tension of a string, the length of a tube, or the speed of airflow. This concept is essential for creating melodies and harmonies. In speech, pitch variation helps convey emotions and emphasize certain words. For example, a higher pitch can indicate excitement, while a lower pitch may suggest seriousness. Understanding pitch variation is crucial in both music and communication, as it enhances expression and meaning.