[Editor's note: After seeing Jack Benny in It's a Mad Mad Mad Mad World, I did an online search and found The Jack Benny Show Podcast (link opens in iTunes). I asked a Showbits reader and historian what he thought of this rebroadcast of the 1932 radio show; his response follows.]
I am also a fan of Jack Benny and am still slowly listening through the entire run of shows that are available. I'm up to the fall of 1950, and the last show on radio was the May 22, 1955 show, before he went entirely to television. Most of them are fun to listen to, and I've certainly become a fan of the show.
The first shows are very different from the formula that he settled upon by the early 1940s, and which he continued until the end of the radio series. Also, the quality of the early shows leaves a LOT to be desired. I didn't try downloading the first podcast to see if this guy cleaned the episodes up at all, but some of them are almost unlistenable they are so bad. Not surprising, however, when you consider that what episodes we have prior to 1939 or 1940 were all recorded on home aluminum disk recorders, rather than on something better quality. Broadcasting companies didn't even feel that recording programs was of any value until the mid-1940s, and it wasn't until the late 1940s that any programs said that they were "transcribed" (recorded); almost everything on the radio was live, and any recordings that existed were done from a radio receiver.
Jack's early shows are reminiscent of the talk show format, where he did some topical humor, almost a monologue like Carson or Leno or Letterman might do today, with some skit thrown in later, and a musical number or two from the ever-present house band. With time he added cast members: Mary Livingston, his wife, was one of the first, then Don Wilson the announcer, then the band leader Phil Harris (later Bob Crosby, Bing's brother), and a tenor to sing a number during the show (first Kenny Baker and then Dennis Day). Rochester, whose real name (Eddie Anderson) was never used on the program as far as I know, came on playing bit parts in the late 1930s, and was so popular that he was added as a regular cast member and even got billing at the start of the show by the early 1940s.
As for the copyright: Apparently, due to changes in the copyright law in the mid 1970s, unless specific actions were taken to copyright a radio program, almost none of them fall under any protection today. Consequently, even shows as late as the CBS Radio Mystery Theater, which aired during the 1970s, are considered today to be in the public domain. As a result, there are thousands of radio programs out there that can be downloaded either for free or for a nominal fee, depending on the host from which they can be downloaded. There are some serious collectors and preservationists out there who offer programs that have been digitized from very good early generation recordings and have also been cleaned up; these are, of course, more expensive (as usual, you get what you pay for).
Some of the best programs I have listened to in the old time radio (OTR) realm are the dramas Escape and Suspense, which did mystery or adventure dramatizations of written short stories of the day. Also some early radio sci-fi like Dimension X and X Minus One have done radio versions of stories by Ray Bradbury, Robert Heinlein, and Isaac Asimov.