These the sessions that were released as two LPs under Echo's "Blues Anthology" series. The complete sessions were also released as a double LP on Adelphi called "Really Chicago's Blues." It's pretty informal stuff - basically, it's kinda like having Johnny Shines, Walter Horton, Big Joe Williams, Sunnyland Slim, etc. sitting around your living room swapping tunes and maybe someone happened to turn a cheap tape recorder on. However, despite the relaxed nature of the proceedings (or perhaps because of it) there are some excellent performances in here if you can get past the sound quality and the generally loose accompaniment. Johnny and Big Joe, in particular, have some great tunes, even if someone should have snatched that damn kazoo out of Joe's hand. (edited review from the defunct Glad Rags Blog).
Filling a request for someone.
Vol. 3: http://www1.zippyshare.com/v/99283382/file.html
Vol. 4: http://www1.zippyshare.com/v/6897056/file.html