Copyright protection is automatic, there is no special action required to copyright a play. As soon as a work of sufficient originality is "fixed in a tangible medium, perceptible to human eye, machine reader or other device". There is no requirement to register or to display a copyright notice for a work to be protected.
The written work is automatically protected by copyright.
Copyright in both the play and the film was renewed, so the play will be protected through 2034, and the film through 2036.
The play is copyright 1979, Peter Shaffer. Copyright of the 1984 movie version would likely belong to the production company. To perform the play, you would almost certainly need permission from a performing rights organization.
1955.
Development of automobiles was affected more by patent than copyright.
no.
No, unfortunately.
Yes you do.
With a license from the copyright holders, yes.
With permission of the copyright holder, yes.
They were required to implement technology to interpret copyright protection information and to prohibit playing unauthorized copies.
Copyright protection on the 1912 play has expired. The 1938 movie is owned by MGM. The various operas and manga would have their own protections.