Well I just have a quick question, something I couldn't find in your article, but can companies copyright modern versions of old melodies?
There are 2 different kinds of copyright there, as far as I (= not a lawyer) know:
- you have the copyright on the actual composition
- you have the copyright on the implementation
So e.g. hypothetically Mozart would hold the copyright to his composition, so everyone who wants to play it (with the notes as composed by him) would have to pay him copyright fees.
Then if you play the piece you just licensed, you hold the copyright to exactly this play. If someone films you and wants to distribute the film, then they would have to pay you copyright fees.
In most western countries the copyright expires after a set amount of time, normally X years after the death of the creator of the piece (I think that is depending on US or EU 50 or 70 years, and might vary depending on medium). This affects the creator itself, and is not affected by any type of transfer of copyright (e.g. when a musician transfers the copyright to a company like Sony, the copyright will still expire X years after the death of the creator), I think.
There are exceptions in the copyright for remixes, satire, and other things.