Music is an art form and cultural activity whose medium is sound organized in time. The general definition of music includes various elements such as pitch (which governs melody and harmony), rhythm (and its associated concepts of rhythm, meter, and articulation), dynamics (loudness and softness), and sonic qualities. Timbre and texture (this is sometimes called the "color" of musical sound). Different styles or types of music may emphasize, de-emphasize or omit certain elements of it. Music is performed with a wide variety of instruments and vocal techniques, from singing to rapping; only instrumental pieces exist, only vocal pieces (such as songs without instrumental accompaniment), and pieces that combine singing and instruments. The word derives from the Greek μουσικ? (mousike; "muse art").

In its most general form, the activity that describes music as an art form or cultural activity includes the creation of musical works (songs, tunes, symphonies, etc.), criticism of music, and the history of music research and aesthetic assessment of music. Ancient Greek and Indian philosophers defined music as tones arranged horizontally as melody and vertically as harmony. Sayings such as "Harmony in all realms" and "That's music to my ears" point to the idea that music is generally ordered and pleasant to listen to. But the 20th century composer John Cage believed that any sound could be music, saying for example: "There is no noise, only sound."