Music is an art form that involves what are sometimes organised sounds and silence, although in some forms of 20th century aleatoric, and indeed improvisational music, as well as most Eastern traditions such as Gamelou, this is not the case. It is expressed in terms of pitch (which includes melody and harmony), rhythm (which includes tempo and meter), and the quality of sound (which includes timbre, articulation, dynamics, and texture).

Music may also involve generative forms in time through the construction of patterns and combinations of natural stimuli, principally sound. Music may be used for artistic or aesthetic, communicative, entertainment, ceremonial or religious purposes and by many composers purly as an academic instrument for study.

Scholars can only speculate about when music began or which cultures had music first. From ancient times people have told stories of its origins. The so-called music of the spheres was thought by Greek philosopher and mathematician Pythagoras in the 6th century bc—and by later classical and medieval philosophers of the Western world—to be a perfectly harmonious music, inaudible on Earth, produced by the movement of the stars and planets. In many non-Western cultures ancient thinkers understood music as part of a system of cosmological, philosophical, or scientific thought. For instance, the musical scale of ancient China, derived through arithmetic from a basic note, reflected the ancient Chinese conception of the organization of the universe. Each degree of the scale was closely related to the cardinal points (north, south, east, west), the elements, the seasons, the planets, the months of the year, colors, materials, numbers, parts of the human body, animals, smells, and so forth. The Chinese found in nature eight different sources of musical sound: metal, stone, silk, bamboo, calabash, terra cotta, skin, and wood.

Many of the elaborate melody patterns of India, called ragas, are believed to have magical or curative powers. Ragas are traditionally played at specific hours or during specific seasons; it is believed that to depart from this timetable would be harmful to the performer and audience. In some tribal societies, music appears to serve as a special form of communication with supernatural beings, and the prominent use of music in modern Christian and Jewish services may be a remnant of such a purpose. Music has always held an important role in religious rituals.