In its most general form, the activities describing music as an art form or cultural activity include the creation of works of music (songs, tunes, symphonies, and so on), the criticism of music, the study of the history of music, and the aesthetic examination of music. Ancient Greek and Indian philosophers defined music in two parts: melodies, as tones ordered horizontally, and harmonies as tones ordered vertically. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound."

The creation, performance, significance, and even the definition of music vary according to culture and social context. Indeed, throughout history, some new forms or styles of music have been criticized as "not being music", including Beethoven's Grosse Fuge string quartet in 1825,early jazz in the beginning of the 1900s and hardcore punk in the 1980s.There are many types of music, including popular music, traditional music, art music, music written for religious ceremonies, and work songs such as chanteys. Music ranges from strictly organized compositions—such as Classical music symphonies from the 1700s and 1800s—through to spontaneously played improvisational music such as jazz, and avant-garde styles of chance-based contemporary music from the 20th and 21st centuries.