Music is an art form and cultural activity whose medium is sound organized in time. The common elements of music are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics (loudness and softness), and the sonic qualities of timbre and texture (which are sometimes termed the "color" of a musical sound). Different styles or types of music may emphasize, de-emphasize or omit some of these elements. Music is performed with a vast range of instruments and vocal techniques ranging from singing to rapping; there are solely instrumental pieces, solely vocal pieces (such as songs without instrumental accompaniment) and pieces that combine singing and instruments. The word derives from Greek μουσική (mousike; "art of the Muses"). See glossary of musical terminology.
Performance is completion of a task with application of knowledge, skills and abilities. In work place, performance or job performance means good ranking with the hypothesized conception of requirements of a task role, whereas citizenship performance means a set of individual activity/contribution (prosocial organizational behavior) that supports the organizational culture. In the performing arts, a performance generally comprises an event in which a performer or group of performers present one or more works of art to an audience. Usually the performers participate in rehearsals beforehand. An effective performance is determined by competency of the performer - level of skill and knowledge. Spencer and McClelland in 1994 defined competency as "a combination of motives, traits, self-concepts, attitudes, cognitive behavior skills (content knowledge)" that helps a performer to differentiate themselves superior from average performers. A performance may also describe the way in which an actor performs. In a solo capacity, it may also refer to a mime artist, comedian, conjurer, or other entertainer.
"For me, the most important thing is the element of chance that is built into a live performance. The very great drawback of recorded sound is the fact that it is always the same. No matter how wonderful a recording is, I know that I couldn't live with it -- even of my own music -- with the same nuances forever."
Aaron Copland, quoted in Classic Essays on Twentieth-Century Music. ISBN 0028645812.