I’m no legal authority, but I would accept the basic premise that, in general, the redistribution of music is illegal. However, there is the doctrine of “fair use,” which is to reproduce a particular work for purposes of criticism, comment, news reporting, teaching, scholarship, and research.

The problem is that in the analog world, such reproduction meant quoting from a book or playing a brief snippet of a song. In today’s digital world, it means posting MP3s, which are an exact (more or less) copy of the original.

It appears that over the past few years, there has arisen a tradition of MP3 blogs that follow particular criteria in the manner in which they post MP3s. Given the response (or lack thereof) from the recording industry, it appears there is a stand-off for now. No law has been established, but it seems that if you follow the rules, you can generally stay out of trouble. There are exceptions, as the Thom Yorke incident demonstrates.

1) You shouldn’t post more than a few tracks from any particular album.

2) You shouldn’t keep MP3s up for more than 1-2 weeks. Ten days seems about right.

Otherwise, if you want to start an MP3 blog, this is probably the definitive guide.