Music is an art form whose medium is sound. Its common elements are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics, and the sonic qualities of timbre and texture. In its most general form the activities describing music as an art form include the production of works of music, the criticism of music, the study of the history of music, and the aesthetic dissemination of music.A selfie is a self-portrait photograph, typically taken with a hand-held digital camera or camera phone. Selfies are often shared on social networking services such as Facebook, Instagram, or Twitter. They are usually flattering and made to appear casual. Most selfies are taken with a camera held at arm's length or pointed at a mirror, rather than by using a self-timer.