 If an instrumental piece is intended to be performed by more than one person, each performer will usually have a separate piece of sheet music, called a "part", to play from.This is especially the case in the publication of works requiring more than four or so performers, though invariably a "full score" is published as well.The sung parts in a vocal work are not usually issued separately today, although this was historically the case, especially before music printing made sheet music widely available.