Frequency is a property of any repeating event, and in music, the phenomenon of pitch is qualitatively assessed via a sound wave's frequency, or number of vibrations per second. Higher sounds have higher frequency, and lower-pitched sounds have lower frequencies.
In music, the phenomenon of pitch can be described by the sound wave's frequency. Frequency is the number of occurrences of a repeating event per unit time; in this case of oscillations of air molecules transferring sound into the ear. Each note can be described by its frequency, expressed in Hertz, and one modern standard of frequency in music puts the note A4 at exactly 440Hz. Frequency is inversely proportional to wavelength.