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.
Vocal music is a type of music performed by one or more singers, either with instrumental accompaniment, or without instrumental accompaniment (a cappella), in which singing provides the main focus of the piece. Music which employs singing but does not feature it prominently is generally considered instrumental music (e.g. the wordless women's choir in the final movement of Holst's The Planets) as is music without singing. Music without any non-vocal instrumental accompaniment is referred to as a cappella.