Music notation or musical notation refers to various systems of writing music. Diverse systems of musical notation have developed in various cultures. In fact, many cultures simply do not notate their music in any form. While this article attempts to present a world-view of musical notation, the dominance of western musical notation throughout most of the world inevitably results in emphasis upon this system. It should be noted that the evolution of any written musical language is akin to the evolution of the written language of speech. First comes spontaneous, unwritten expression; later comes a system of written language. Each has its merits, particularly in the realm of music. Music which is not notated can convey the natural and spontaneous aspects of the human spirit, free of preconceived parameters of rhythm and pitch. Ironically, in western music, many of today's most successful song-writers can neither read nor write music. Their compositions result from improvisation. In juxtaposition, the leading classical performers are primarily committed to written scores, since music which is notated can preserve the inspiration of some of the most profound of musical thoughts.