Brady asks about Happy Birthday. Great example because for a long time you did not see or hear it in TV, or film, because Warners enforced copyright over it. Yes, you had to pay Warner Music to sing Happy Birthday. However, copyright lawyers were always suspicious of this and so are trying to prove that Warner’s don’t have copyright, and are wanting to recover money to pay people who have been sued, or paid for it, in the first place. For more see wikipedia and if nothing else realise that US copyright is different to everybody else’s. (We don’t need to register or publish a copyright symbol for copyright to apply.)