Ballet is a formalised kind of performance dance, which originated in the Italian Renaissance courts of the 15th century, and which was further developed in France, Russia, and Britain as a concert dance form. The early portions preceded the invention of the proscenium stage and were presented in large chambers with most of the audience seated on tiers or galleries on three sides of the dancing floor. It has since become a highly technical form of dance with its own vocabulary. It is primarily performed with the accompaniment of classical music and has been influential as a form of dance globally. Ballet has been taught in ballet schools around the world, which use their own cultures and societies to inform the art. Ballet dance works (ballets) are choreographed and performed by trained artists, include mime and acting, and are set to music (usually orchestral but occasionally vocal). It is a poised style of dance that incorporates the foundational techniques for many other dance forms. This genre of dance is very hard to master and requires much practice. It is best known in the form of Late Romantic Ballet or Ballet Blanc, which preoccupies itself with the female dancer to the exclusion of almost all else, focusing on pointe work, flowing, precise acrobatic movements, and often presenting the dancers in the conventional short white French tutu. Later developments include expressionist ballet, Neoclassical ballet, and elements of Modern dance.