There is no such thing! The copyright exists the very moment you create any work of art or performance of any sort.
The only secure method of establishing copyright is to publish, e.g. release a CD that is registered with PPL, MCPS, or on YouTube or performance on Blu-Ray or have the thing broadcast in some way.
There are totally bogus registration sites and incredibly stupid ideas like the sealed envelope idea (that is regularly thrown out of court!) and all sorts of other bonkers ideas - stay away from these and don't waste your time or money on them!
If you want to establish a name - let us say that you wish that your band (or movie, or brand of instrument or studio or indeed anything else) is to be called 'Pubis Berk and the Deltoids' and you seek to protect that name, you must register the name as a trademark with the government 'Intellectual Property Office' (known to its' friends as the IPO) and that can take up to three months and costs £170. That is of course not the same thing as copyright, but it is worth remembering.
Nothing is quite as galling as trading as 'X' for a few years, only to discover a 'Cease and Desist!' letter on the doormat from someone who has just registered that name!
There are different types of copyright and other rights. If you write a book, the words are subject to intellectual copyright. The format or idea or premise for the story-line is also subject to intellectual copyright. The layout is subject to mechanical copyright. Turn it into a musical and the script is also subject to those copyrights. The music is then subject to two intellectual copyrights (words and music) and if recorded, mechanical.
Some rights, such as image rights, only exist in a few territories and in many counties, copyrights are routinely abused. The face of a famous person may be registered as a trademark however.
Any original work may be copyrighted - for example, an original new design for a mic-pre-amp may not just be patented, but also subject to copyright laws!https://en.wikipedia.org/wiki/Copyright