The field leader in drum & bugle corps is called a drum major. Some corps appoint more than one, but there is usually one designated chief drum major who leads the corps in both marching direction and musical direction. Traditional corps drum majors are effective showmen who command the corps in all venues. Early in the 20th Century, commands were usually issued either through a mace or baton, and/or with whistle signals. Eventually this evolved into vocal commands and manual signals, although military units still maintain the baton-signaling methods.