On September 9th, EMI released a remastered version of the entire Beatles catalogue -- the first remix since 1987. And now the Beatles are once again back on top of the charts. If you're wondering whether to buy the remastered versions at all, or whether to buy the stereo or mono box sets (or some combination of the two), or if you're simply wondering what goes into remastering the Fab Four's complete body of work, then you will be interested in this interview with Beatles historian Kevin Howlett, who helped write the liner notes for the new releases. In this conversation with NPR's All Songs Considered (MP3 - iTunes - RSS Feed), Howlett describes what the remastering involved, and then compares the old versions to the new versions (both mono and stereo). When you're done listening to this 20+ minute interview, you'll have a much better sense of what this long-awaited remastering delivers. You can listen with the player below, or via the links posted above.