"...the Live Music Archive...is a community committed to providing the highest quality live concerts in a lossless, downloadable format. The Internet Archive has teamed up with etree.org to preserve and archive as many live concerts as possible for current and future generations to enjoy. All music in this Collection is from trade-friendly artists and is strictly noncommercial, both for access here and for any further distribution. Artists' commercial releases are off-limits."
Incredible selection of live bootleg, all legal. The "lossless" format is best quality-wise, but songs are 25-30 mb each, making one concert as much as a gig. Try "Browse bands with MP3/Ogg versions" to download shorter files.
To convert the huge lossless files requires a software program to decode them. They arrive in .shn format. Information about how to do all that is in the web site.
My recommendation: anything by Martin Sexton to start with.
http://www.archive.org/audio/etree.php
