Music is the art of arranging sound to create some combination of form, harmony, melody, rhythm, or expressive content. It is one of the arts that, in one guise or another, permeates every human society. Modern music is heard in a bewildering profusion of styles, some new, others derived from past eras. The popularity of musical forms and genres testifies to an almost universal belief in the power of music to influence human emotions, to inspire ideals that could lead to a culture of peace, and to convey important information about the world around us.
The word music derives from the Greek words for voice and emotion, and refers to the human response to organized sound, which involves elements like melody, harmony, timbre, and form. It is generally distinguished from simple noise by its structure and compositional principles, as well as from other forms of artistic expression that may use sounds, such as dance or painting. Some definitions include vocal music, but the most inclusive and widely accepted definition includes any organized sound that has emotional expressive qualities.
Music can be divided into different categories, or styles, based on a number of criteria, including form, genre, instrumentation, tone, and harmonic structure. It is also categorized according to the purpose it serves, whether as entertainment, religious, educational, ceremonial, or other. Some of the most famous styles of music are opera, jazz, rock and roll, symphony, blues, country, and hip hop.
Whether it is meant to be played on a piano, performed by a full orchestra, or simply to be enjoyed by the listener, each type of music has a unique way of making an impression. Some of these are purely aesthetic: they make the listener feel happy, sad, excited or inspired. Other types of music communicate important ideas or information, such as history or social commentary, through lyrics.
While some listeners will find any kind of music appealing, many are drawn to certain kinds. The reason for this has been attributed to the way that specific musics are associated with particular cultures, or the way that specific notes or instruments are used to express feelings and ideas.
The ancient Greeks saw a connection between a particular music and the character of its creators, a view echoed later by Plato (428-348/347 bce), who viewed earthly music as a department of ethics and a shadow of the divine order of heavenly harmony. For him, a style of music should be simple and straightforward; melodic and rhythmic complexities would detract from moral integrity.
The idea of a symbolic meaning in music persists to this day, though it has become a point of controversy among philosophers and critics. Referentialists insist that music can and does contain meaningful references, while nonreferentialists (often called formalists) assert that the only meaning in a piece of music is the music itself. Attempts to describe the nature of these meanings through language tend to fall short of the complexity and variety of music experience, so verbal explanation often seems to confuse more than it clarifies.