I don't think it's a good idea.
Some people will be charged without ever downloading any music (yes they still exist) and, as said before, if they gets this through, then what's next? Then they will have to do the same for movies, software, games (if that isn't categorised under software) and maybe even more in the future.
Also, who's going to check whether the extra money actually goes to the artists who should receive it? Here in the Netherlands we have something called "Stichting Thuiskopie" which should receive and distribute these kinds of fees (eg. we have a fee on empty cds/dvds/etc, that's why I buy those in germany
) but they have been criticised multiple times for keeping too much of the money for themselves.
Besides, I can already download music and movies legally here. Downloading pirated software is illegal, and so is uploading of any of the above, but I'm willing to take that risk.