Different lengths for different rights
AndyS: you were partly right - there are many different types of rights involved in any one song: the composer of the music has rights (life of the artist + 70 years), the lyricist has rights (life of the artist + 70 years), and the people who actually play on a particular recording of the track have rights (50 years).
This is what the music industry is talking about when the say they want 'parity' - authors, composers, songwriters and artists get life + 70, why don't the performers? Maybe because you end up with f**kers like James Joyce's grandson who forbids the people who continue to line his pockets with cash the right to read aloud the works they love so much at a celebration of his benefactors life (see the introduction here: http://www.law.ed.ac.uk/ahrc/script-ed/vol2-3/bloomsday.asp)
I do love the whole 'but we have no pension' argument. Um, when you recorded the song in the 1950's, you knew when your royalties would stop. But you decided not to save some of the money. And when in the 1980's you begun to get old and realised that you would never have another hit single but were still receiving royalty cheques, did you not start to think that maybe, just maybe, like everyone else in the world, that you might want to start putting some of that money away for a rainy day. But no, you went on spending it, gambling that the government would extend the term of copyright. Guess what buddy, you lost.
Well, at least for the moment, until the EU steps in to extend the term. It's alright, the Germans will come along and help feed you in your old age.