It is useful to view all of the media together, ranging from the individual performer appearing in the flesh before his audience to the complex presentations of electronic media. They may be compared in terms of the relationship of the performer to his audience. The media also vary in the kind of performance on which they can draw, either derivatively or creatively. Media borrow from each other just as Greek drama drew on ancient myths and legends and Renaissance drama on classical and contemporary material. The voracious demands of 20th century media have driven producers and scriptwriters to acquire the rights to existent material in other media, particularly the novel and drama. Radio and television have overlapped increasingly with journalism, with many journalists becoming broadcasters and commentators. However, much of the borrowing has been mechanical and technical rather than artistic in nature. The invention of magnetic tape for recording both sound and video signals ha...