This may be extremely late blooming on my part, but I just discovered the site Daytrotter. It's a music blog that has not only reviews and artist profiles, but live sessions from basically every band they profile. I think that they basically record and write about 5 bands a week, and then all of the songs from the session are available for free download.
I went on a downloading spree once I found this. I recommend the Blitzen Trapper sessions and The National session.
http://www.daytrotter.com/
