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.Street performance or busking is the practice of performing in public places, for gratuities. In many countries the rewards are generally in the form of money but other gratuities such as food, drink or gifts may be given. Street performance is practiced all over the world by men, women and children and dates back to antiquity. In English-speaking countries people engaging in this practice are called street performers or buskers.