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.
Human activities have strongly modified the biogeochemical cycles of metallic trace elements (MTEs) increasing their fluxes towards and between surface environments. New isotope data has fostered better models of MTE sources, transfer and reactivities in dynamic and multi-sources systems, as required for targeting emission controlled strategies to combat origins and consequences of metal contamination.