Lots of bands allow (even encourage) their fans to trade recordings of their concerts. The standard file format for these recordings is FLAC, a lossless codec (meaning it preserves all of the audio data, unlike mp3). The standard place to get these recordings is archive.org.
These concerts are great (I have been downloading them at random and finding the average quality to be high), but there is a little work involved in getting them nicely imported. In particular, you have you cut-and-paste or re-type the metadata (artist, album, and track names). This script does all that for you. Please give it a try, and as always, let me know if you have questions or problems.
Not particularly useful if you are sitting in front of your Mac; I wrote it so that I could rate songs on my home computer while listening on my iPod at work. Now that I have a later iPod which allows me to rate directly, I rarely use this.
It features a nice routine for formatting text on the fly into a
List albums with unrated tracks, ordered by number of plays. I am currently on a rating kick, trying to rate a lot more tracks, and trying to do so one album at a time so I can give the best tracks on each album 4 or 5 stars.
Library to parse the text file created by iTunes's "Export Song List" command.