Pitch is closely related to frequency or a number of vibrations or cycles per second but the two are not equivalent. Frequency is an objective, scientific concept, whereas pitch is more subjective and dependent on human interpretation. Sound waves themselves do not have pitch, yet their oscillations can be measured to obtain a frequency. It takes the human mind to map the internal musical quality of pitch. In music pitches are given letter names and then organized and identified in relationships to each other as scales and chords and melodies etc.